From 50851c4ee3a48545ebd9353bbd83133a41855e79 Mon Sep 17 00:00:00 2001
From: Olivier Mattelaer <olivier.mattelaer@uclouvain.be>
Date: Sat, 24 Oct 2026 16:12:31 +0200
Subject: [PATCH 1/5] CI: run IOTests and the madevent acceptance tests on the
 self-hosted alma10 runners

On a self-hosted runner restore_heptools no longer uses the GitHub caches
(built on ubuntu, with /home/runner baked into the install): each machine
builds the missing HEPTools components once into its own ~/.cache/HEPtools
(selfhosted_heptools). The restore_heptools_* actions use $HOME instead of
/home/runner and find the lhapdf/rivet/contur python modules on other images.
Fork PRs and the two matrix jobs stay on ubuntu-24.04.
---
 .github/actions/restore_heptools/action.yml   | 19 +++--
 .../restore_heptools_contur/action.yml        | 27 +++++--
 .../actions/restore_heptools_emela/action.yml |  2 +-
 .../restore_heptools_lhapdf/action.yml        | 27 ++++---
 .../restore_heptools_looptools/action.yml     |  4 +-
 .../restore_heptools_pythia8/action.yml       |  4 +-
 .../actions/selfhosted_heptools/action.yml    | 13 ++++
 .../selfhosted_heptools/build_heptools.sh     | 72 +++++++++++++++++++
 .github/workflows/IOtest.yml                  | 20 ++++--
 .github/workflows/acceptancetest_madevent.yml | 48 +++++++++----
 10 files changed, 191 insertions(+), 45 deletions(-)
 create mode 100644 .github/actions/selfhosted_heptools/action.yml
 create mode 100755 .github/actions/selfhosted_heptools/build_heptools.sh

diff --git a/.github/actions/restore_heptools/action.yml b/.github/actions/restore_heptools/action.yml
index eab077c740..c562b0b020 100644
--- a/.github/actions/restore_heptools/action.yml
+++ b/.github/actions/restore_heptools/action.yml
@@ -24,6 +24,7 @@ runs:
     # every restore_heptools_* action.
     - name: restore full cache
       id: heptools-cache
+      if: runner.environment != 'self-hosted'
       uses: actions/cache/restore@v5
       with:
         path: ~/.cache/HEPtools
@@ -49,23 +50,29 @@ runs:
         tools: lhapdf boost pythia8 emela contur looptools
         mode: report
 
+    # A self-hosted runner does not use the GitHub caches at all: it keeps its
+    # own ~/.cache/HEPtools and builds what is missing there (once per machine).
+    - name: build HEPTools on this machine
+      if: runner.environment == 'self-hosted'
+      uses: ./.github/actions/selfhosted_heptools
+
     # setup other environment of previous level of cache
     # try to use their cache if previous cache failed or content is incomplete
     - uses: ./.github/actions/restore_heptools_lhapdf
       with:
-        setup_only: ${{ steps.heptools-cache.outputs.cache-matched-key != '' && steps.validate-cache.outputs.valid == 'true' }}
+        setup_only: ${{ runner.environment == 'self-hosted' || (steps.heptools-cache.outputs.cache-matched-key != '' && steps.validate-cache.outputs.valid == 'true') }}
     - uses: ./.github/actions/restore_heptools_boost
       with:
-        setup_only: ${{ steps.heptools-cache.outputs.cache-matched-key != '' && steps.validate-cache.outputs.valid == 'true' }}
+        setup_only: ${{ runner.environment == 'self-hosted' || (steps.heptools-cache.outputs.cache-matched-key != '' && steps.validate-cache.outputs.valid == 'true') }}
     - uses: ./.github/actions/restore_heptools_pythia8
       with:
-        setup_only: ${{ steps.heptools-cache.outputs.cache-matched-key != '' && steps.validate-cache.outputs.valid == 'true' }}
+        setup_only: ${{ runner.environment == 'self-hosted' || (steps.heptools-cache.outputs.cache-matched-key != '' && steps.validate-cache.outputs.valid == 'true') }}
     - uses: ./.github/actions/restore_heptools_emela
       with:
-        setup_only: ${{ steps.heptools-cache.outputs.cache-matched-key != '' && steps.validate-cache.outputs.valid == 'true' }}
+        setup_only: ${{ runner.environment == 'self-hosted' || (steps.heptools-cache.outputs.cache-matched-key != '' && steps.validate-cache.outputs.valid == 'true') }}
     - uses: ./.github/actions/restore_heptools_contur
       with:
-        setup_only: ${{ steps.heptools-cache.outputs.cache-matched-key != '' && steps.validate-cache.outputs.valid == 'true' }}
+        setup_only: ${{ runner.environment == 'self-hosted' || (steps.heptools-cache.outputs.cache-matched-key != '' && steps.validate-cache.outputs.valid == 'true') }}
     - uses: ./.github/actions/restore_heptools_looptools
       with:
-        setup_only: ${{ steps.heptools-cache.outputs.cache-matched-key != '' && steps.validate-cache.outputs.valid == 'true' }}
+        setup_only: ${{ runner.environment == 'self-hosted' || (steps.heptools-cache.outputs.cache-matched-key != '' && steps.validate-cache.outputs.valid == 'true') }}
diff --git a/.github/actions/restore_heptools_contur/action.yml b/.github/actions/restore_heptools_contur/action.yml
index de42f53f9c..88520df3ad 100644
--- a/.github/actions/restore_heptools_contur/action.yml
+++ b/.github/actions/restore_heptools_contur/action.yml
@@ -33,10 +33,10 @@ runs:
 
     - run: |
         cd $GITHUB_WORKSPACE
-        echo "hepmc3_path = /home/runner/.cache/HEPtools/hepmc3" >>  input/mg7_configuration.txt
-        echo "rivet_path = /home/runner/.cache/HEPtools/rivet" >>  input/mg7_configuration.txt
-        echo "yoda_path = /home/runner/.cache/HEPtools/yoda" >>  input/mg7_configuration.txt
-        echo "contur_path = /home/runner/.cache/HEPtools/contur" >>  input/mg7_configuration.txt
+        echo "hepmc3_path = $HOME/.cache/HEPtools/hepmc3" >>  input/mg7_configuration.txt
+        echo "rivet_path = $HOME/.cache/HEPtools/rivet" >>  input/mg7_configuration.txt
+        echo "yoda_path = $HOME/.cache/HEPtools/yoda" >>  input/mg7_configuration.txt
+        echo "contur_path = $HOME/.cache/HEPtools/contur" >>  input/mg7_configuration.txt
         # Only point MG5 at fastjet if it is really there.  The cache restore
         # above is best-effort (fail-on-cache-miss is false, and warm_cache
         # deletes the contur/heptools caches ~30 min before it re-saves them,
@@ -46,7 +46,7 @@ runs:
         # fastjet/ClusterSequence.hh.  Without the line MG5 uses fjcore, which
         # is a working fallback: the contur/rivet jobs still fail, loudly and on
         # their own, but the numbered acceptance jobs no longer fail with them.
-        FJ=/home/runner/.cache/HEPtools/fastjet/bin/fastjet-config
+        FJ=$HOME/.cache/HEPtools/fastjet/bin/fastjet-config
         if [ -x "$FJ" ]; then
           echo "fastjet = $FJ" >>  input/mg7_configuration.txt
         else
@@ -57,11 +57,24 @@ runs:
     - name: set pythonpath for ubuntu22
       if: ${{ env.HEPTOOLS_IMAGE == 'ubuntu22' }}
       run: |
-          echo "PYTHONPATH=$PYTHONPATH:/home/runner/.cache/HEPtools/contur/python3.10/:/home/runner/.cache/HEPtools/rivet/python3.10/:/home/runner/.cache/HEPtools/rivet/local/python3.10/" >> $GITHUB_ENV
+          echo "PYTHONPATH=$PYTHONPATH:$HOME/.cache/HEPtools/contur/python3.10/:$HOME/.cache/HEPtools/rivet/python3.10/:$HOME/.cache/HEPtools/rivet/local/python3.10/" >> $GITHUB_ENV
       shell: bash
 
     - name: set pythonpath for ubuntu24
       if: ${{ env.HEPTOOLS_IMAGE == 'ubuntu24' }}
       run: |
-          echo "PYTHONPATH=$PYTHONPATH:/home/runner/.cache/HEPtools/contur/python3.12/:/home/runner/.cache/HEPtools/rivet/python3.12/:/home/runner/.cache/HEPtools/rivet/local/python3.10/" >> $GITHUB_ENV
+          echo "PYTHONPATH=$PYTHONPATH:$HOME/.cache/HEPtools/contur/python3.12/:$HOME/.cache/HEPtools/rivet/python3.12/:$HOME/.cache/HEPtools/rivet/local/python3.10/" >> $GITHUB_ENV
+      shell: bash
+    # any other image (a self-hosted runner, where ImageOS is unset): take the
+    # python modules wherever this machine's build put them
+    - name: set pythonpath for other images
+      if: ${{ env.HEPTOOLS_IMAGE != 'ubuntu22' && env.HEPTOOLS_IMAGE != 'ubuntu24' }}
+      run: |
+        P=$PYTHONPATH
+        for d in $HOME/.cache/HEPtools/contur/python3* $HOME/.cache/HEPtools/rivet/python3* \
+                 $HOME/.cache/HEPtools/rivet/local/python3* \
+                 $HOME/.cache/HEPtools/{rivet,yoda}/{,local/}lib*/python3*/*-packages; do
+          [ -d "$d" ] && P=$P:$d
+        done
+        echo "PYTHONPATH=$P" >> $GITHUB_ENV
       shell: bash
diff --git a/.github/actions/restore_heptools_emela/action.yml b/.github/actions/restore_heptools_emela/action.yml
index 5df5ee0645..3e0a19043c 100644
--- a/.github/actions/restore_heptools_emela/action.yml
+++ b/.github/actions/restore_heptools_emela/action.yml
@@ -34,5 +34,5 @@ runs:
 
     - run: |
         cd $GITHUB_WORKSPACE
-        echo "eMELA = /home/runner/.cache/HEPtools/bin/eMELA-config" >>       input/mg7_configuration.txt
+        echo "eMELA = $HOME/.cache/HEPtools/bin/eMELA-config" >>       input/mg7_configuration.txt
       shell: bash
diff --git a/.github/actions/restore_heptools_lhapdf/action.yml b/.github/actions/restore_heptools_lhapdf/action.yml
index 83b0379839..e000605641 100644
--- a/.github/actions/restore_heptools_lhapdf/action.yml
+++ b/.github/actions/restore_heptools_lhapdf/action.yml
@@ -36,23 +36,23 @@ runs:
 
     - run: |
         cd $GITHUB_WORKSPACE
-        echo "heptools_install_dir=/home/runner/.cache/HEPtools" >> input/mg7_configuration.txt
-        echo "lhapdf = /home/runner/.cache/HEPtools/bin/lhapdf-config" >>       input/mg7_configuration.txt
-        echo "lhapdf_py3 = /home/runner/.cache/HEPtools/bin/lhapdf-config" >>       input/mg7_configuration.txt
-        echo "LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/home/runner/.cache/HEPtools/lhapdf6_py3//lib" >> $GITHUB_ENV
-        echo "LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/home/runner/.cache/HEPtools/lib" >> $GITHUB_ENV
+        echo "heptools_install_dir=$HOME/.cache/HEPtools" >> input/mg7_configuration.txt
+        echo "lhapdf = $HOME/.cache/HEPtools/bin/lhapdf-config" >>       input/mg7_configuration.txt
+        echo "lhapdf_py3 = $HOME/.cache/HEPtools/bin/lhapdf-config" >>       input/mg7_configuration.txt
+        echo "LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$HOME/.cache/HEPtools/lhapdf6_py3//lib" >> $GITHUB_ENV
+        echo "LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$HOME/.cache/HEPtools/lib" >> $GITHUB_ENV
       shell: bash
 
     - name: set pythonpath for ubuntu22
       if: ${{ env.HEPTOOLS_IMAGE == 'ubuntu22' }}
       run: |
-        echo "PYTHONPATH=$PYTHONPATH:/home/runner/.cache/HEPtools/lhapdf6_py3/lib/python3.10/dist-packages" >> $GITHUB_ENV
+        echo "PYTHONPATH=$PYTHONPATH:$HOME/.cache/HEPtools/lhapdf6_py3/lib/python3.10/dist-packages" >> $GITHUB_ENV
       shell: bash 
 
     - name: set pythonpath for ubuntu24
       if: ${{ env.HEPTOOLS_IMAGE == 'ubuntu24' }}
       run: |
-        echo "PYTHONPATH=$PYTHONPATH:/home/runner/.cache/HEPtools/lhapdf6_py3/lib/python3.12/dist-packages" >> $GITHUB_ENV
+        echo "PYTHONPATH=$PYTHONPATH:$HOME/.cache/HEPtools/lhapdf6_py3/lib/python3.12/dist-packages" >> $GITHUB_ENV
       shell: bash
 
     # The run_card default PDF sets: NNPDF40_lo_as_01180 (mg7 [beam] pdf and the
@@ -63,9 +63,20 @@ runs:
     # on the set being present and would all self-skip (test_manager.py counts a
     # skip as a failure). Fetching them here is a no-op once the cache carries
     # them. Non-fatal on failure: the tests skip as they did before.
+    # any other image (a self-hosted runner, where ImageOS is unset): take the
+    # python bindings wherever this machine's build put them
+    - name: set pythonpath for other images
+      if: ${{ env.HEPTOOLS_IMAGE != 'ubuntu22' && env.HEPTOOLS_IMAGE != 'ubuntu24' }}
+      run: |
+        P=$PYTHONPATH
+        for d in $HOME/.cache/HEPtools/lhapdf6_py3/lib*/python3*/*-packages; do
+          [ -d "$d" ] && P=$P:$d
+        done
+        echo "PYTHONPATH=$P" >> $GITHUB_ENV
+      shell: bash
     - name: ensure the default PDF sets are present
       run: |
-        DATADIR=/home/runner/.cache/HEPtools/lhapdf6_py3/share/LHAPDF
+        DATADIR=$HOME/.cache/HEPtools/lhapdf6_py3/share/LHAPDF
         for SET in NNPDF40_lo_as_01180 NNPDF40_nlo_as_01180 NNPDF40_nlo_as_01180_nf_4; do
           if [ -d "$DATADIR" ] && [ ! -d "$DATADIR/$SET" ]; then
             ( cd "$DATADIR" \
diff --git a/.github/actions/restore_heptools_looptools/action.yml b/.github/actions/restore_heptools_looptools/action.yml
index 157d381b32..7d7dddde44 100644
--- a/.github/actions/restore_heptools_looptools/action.yml
+++ b/.github/actions/restore_heptools_looptools/action.yml
@@ -28,6 +28,6 @@ runs:
     # this ignore cuttools/iregi cache ... ok but we should try to fix that
     - run: |
         cd $GITHUB_WORKSPACE
-        echo "ninja = /home/runner/.cache/HEPtools/ninja/lib" >>  input/mg7_configuration.txt
-        echo "collier = /home/runner/.cache/HEPtools/collier" >>  input/mg7_configuration.txt
+        echo "ninja = $HOME/.cache/HEPtools/ninja/lib" >>  input/mg7_configuration.txt
+        echo "collier = $HOME/.cache/HEPtools/collier" >>  input/mg7_configuration.txt
       shell: bash
diff --git a/.github/actions/restore_heptools_pythia8/action.yml b/.github/actions/restore_heptools_pythia8/action.yml
index 1b01937b07..921c7570c8 100644
--- a/.github/actions/restore_heptools_pythia8/action.yml
+++ b/.github/actions/restore_heptools_pythia8/action.yml
@@ -34,6 +34,6 @@ runs:
 
     - run: |
         cd $GITHUB_WORKSPACE
-        echo "pythia8_path = /home/runner/.cache/HEPtools/pythia8" >>  input/mg7_configuration.txt
-        echo "hepmc_path = /home/runner/.cache/HEPtools/hepmc" >>  input/mg7_configuration.txt
+        echo "pythia8_path = $HOME/.cache/HEPtools/pythia8" >>  input/mg7_configuration.txt
+        echo "hepmc_path = $HOME/.cache/HEPtools/hepmc" >>  input/mg7_configuration.txt
       shell: bash
diff --git a/.github/actions/selfhosted_heptools/action.yml b/.github/actions/selfhosted_heptools/action.yml
new file mode 100644
index 0000000000..c8af95470d
--- /dev/null
+++ b/.github/actions/selfhosted_heptools/action.yml
@@ -0,0 +1,13 @@
+name: Build HEPTools on a self-hosted runner
+description: >
+  A self-hosted runner keeps ~/.cache/HEPtools on its own disk from one job to
+  the next, so instead of the GitHub caches (built by warm_cache.yml on, and
+  with paths baked in for, the ubuntu image) each machine builds the missing
+  components itself, once, the first time a job needs them. A component that
+  fails to build only warns: the tests that need it then fail, the others run.
+runs:
+  using: composite
+  steps:
+    - name: Build the missing HEPTools components
+      shell: bash
+      run: bash "${{ github.action_path }}/build_heptools.sh"
diff --git a/.github/actions/selfhosted_heptools/build_heptools.sh b/.github/actions/selfhosted_heptools/build_heptools.sh
new file mode 100755
index 0000000000..0fbceab5ec
--- /dev/null
+++ b/.github/actions/selfhosted_heptools/build_heptools.sh
@@ -0,0 +1,72 @@
+#!/usr/bin/env bash
+# Build into ~/.cache/HEPtools every HEPTools component that check_heptools
+# does not find complete there, with the same install commands as the
+# warm_cache.yml jobs. Runs from a pristine copy of the checked-out tree, so
+# the job's own tree is left as checked out.
+set -u
+HEP="$HOME/.cache/HEPtools"
+CHECK="$GITHUB_WORKSPACE/.github/actions/check_heptools/check_heptools.sh"
+export MAKEFLAGS="-j$(nproc)"
+mkdir -p "$HEP"
+
+# one build at a time per machine, should several runners share this home
+exec 9> "$HEP.lock"
+flock 9
+
+complete() {
+    HEPTOOLS_PREFIX="$HEP" CHECK_MODE=fatal GITHUB_OUTPUT= bash "$CHECK" "$1" > /dev/null 2>&1
+}
+
+SRC=""
+prepare_src() {
+    [ -n "$SRC" ] && return
+    SRC=$(mktemp -d "${RUNNER_TEMP:-/tmp}/heptools-src.XXXXXX")
+    git -C "$GITHUB_WORKSPACE" archive HEAD | tar -x -C "$SRC"
+    cp "$SRC/input/.mg7_configuration_default.txt" "$SRC/input/mg7_configuration.txt"
+    echo "heptools_install_dir=$HEP" >> "$SRC/input/mg7_configuration.txt"
+    cp "$SRC/Template/LO/Source/.make_opts" "$SRC/Template/LO/Source/make_opts"
+}
+
+mg_install() {
+    printf '%s\n' "$@" > "$SRC/cmd"
+    (cd "$SRC" && ./bin/madgraph cmd)
+}
+
+build_lhapdf() {
+    mg_install "install lhapdf6"
+    cd "$HEP/lhapdf6_py3/share/LHAPDF" || return 1
+    for SET in NNPDF23_nlo_as_0118_qed cteq6l1 NNPDF40_lo_as_01180 NNPDF40_nlo_as_01180 \
+               NNPDF40_nlo_as_01180_nf_4 NNPDF40MC_lo_as_01180 NNPDF23_lo_as_0130_qed; do
+        [ -d "$SET" ] && continue
+        wget -q "https://lhapdfsets.web.cern.ch/current/$SET.tar.gz" \
+            && tar -xzpf "$SET.tar.gz" && rm -f "$SET.tar.gz"
+    done
+}
+build_boost()   { mg_install "install boost"; }
+build_pythia8() { mg_install "install pythia8"; }
+build_emela()   { mg_install "install eMELA"; }
+build_contur()  { mg_install "install rivet" "install contur"; }
+build_looptools() {
+    (cd "$SRC/vendor/IREGI/src" && make) || return 1
+    (cd "$SRC/vendor/CutTools" && make) || return 1
+    mkdir -p "$HEP/IREGI/src" "$HEP/CutTools/lib"
+    cp "$SRC/vendor/IREGI/src/libiregi.a" "$HEP/IREGI/src/"
+    cp "$SRC/vendor/CutTools/includects/libcts.a" "$SRC/vendor/CutTools/includects/mpmodule.mod" "$HEP/CutTools/lib"
+    mg_install "install collier" "install ninja"
+}
+
+# dependency order: emela needs boost, contur needs pythia8 (hepmc)
+for tool in lhapdf boost pythia8 emela contur looptools; do
+    if complete "$tool"; then
+        echo "$tool: already built on $RUNNER_NAME"
+        continue
+    fi
+    echo "::group::building $tool on $RUNNER_NAME (first use on this machine)"
+    prepare_src
+    ( "build_$tool" )
+    echo "::endgroup::"
+    complete "$tool" || echo "::warning::HEPTools $tool could not be built on $RUNNER_NAME"
+done
+
+[ -n "$SRC" ] && rm -rf "$SRC"
+exit 0
diff --git a/.github/workflows/IOtest.yml b/.github/workflows/IOtest.yml
index 2bd41a6a93..b22e12dcf0 100644
--- a/.github/workflows/IOtest.yml
+++ b/.github/workflows/IOtest.yml
@@ -45,7 +45,9 @@ jobs:
     #   IOtest_fks IOtest_fd_gauge IOtest_export
     #   IOtest_unit_proc IOtest_ewsudakov
     # Each keeps its own steps, run even when an earlier one failed.
-    runs-on: ubuntu-24.04
+    # Runs on the self-hosted alma10 runners (cern1, ...) to spare the hosted queue;
+    # fork PRs stay on ubuntu-24.04 so outside code never runs on our machines.
+    runs-on: ${{ github.event.pull_request.head.repo.fork && 'ubuntu-24.04' || fromJSON('["self-hosted", "alma10"]') }}
     steps:
       - uses: actions/checkout@v5
 
@@ -101,7 +103,9 @@ jobs:
 
   # Loop squared-order IOTest – needs UFO model cache (from unittest_29)
   IOtest_loop_sqso:
-    runs-on: ubuntu-24.04
+    # Runs on the self-hosted alma10 runners (cern1, ...) to spare the hosted queue;
+    # fork PRs stay on ubuntu-24.04 so outside code never runs on our machines.
+    runs-on: ${{ github.event.pull_request.head.repo.fork && 'ubuntu-24.04' || fromJSON('["self-hosted", "alma10"]') }}
     steps:
       - uses: actions/checkout@v5
       - uses: ./.github/actions/restore_ufomodel
@@ -116,7 +120,9 @@ jobs:
     # former jobs, run one after the other: IOtest_acceptance_proc
     #   IOtest_matchbox
     # Each keeps its own steps, run even when an earlier one failed.
-    runs-on: ubuntu-24.04
+    # Runs on the self-hosted alma10 runners (cern1, ...) to spare the hosted queue;
+    # fork PRs stay on ubuntu-24.04 so outside code never runs on our machines.
+    runs-on: ${{ github.event.pull_request.head.repo.fork && 'ubuntu-24.04' || fromJSON('["self-hosted", "alma10"]') }}
     steps:
       - uses: actions/checkout@v4
       - uses: ./.github/actions/checkout_mg5
@@ -147,7 +153,9 @@ jobs:
   IOtest_bundle_3:
     # former jobs, run one after the other: IOtest_TIR IOtest_loop_induced
     # Each keeps its own steps, run even when an earlier one failed.
-    runs-on: ubuntu-24.04
+    # Runs on the self-hosted alma10 runners (cern1, ...) to spare the hosted queue;
+    # fork PRs stay on ubuntu-24.04 so outside code never runs on our machines.
+    runs-on: ${{ github.event.pull_request.head.repo.fork && 'ubuntu-24.04' || fromJSON('["self-hosted", "alma10"]') }}
     steps:
       - uses: actions/checkout@v4
       - uses: ./.github/actions/checkout_mg5
@@ -176,7 +184,9 @@ jobs:
 
   # Gnuplot histogram output IOTest (from acceptancetest_100)
   IOtest_gnuplot:
-    runs-on: ubuntu-24.04
+    # Runs on the self-hosted alma10 runners (cern1, ...) to spare the hosted queue;
+    # fork PRs stay on ubuntu-24.04 so outside code never runs on our machines.
+    runs-on: ${{ github.event.pull_request.head.repo.fork && 'ubuntu-24.04' || fromJSON('["self-hosted", "alma10"]') }}
     steps:
       - uses: actions/checkout@v4
       - uses: ./.github/actions/checkout_mg5
diff --git a/.github/workflows/acceptancetest_madevent.yml b/.github/workflows/acceptancetest_madevent.yml
index 68164e7016..64f39f2f37 100644
--- a/.github/workflows/acceptancetest_madevent.yml
+++ b/.github/workflows/acceptancetest_madevent.yml
@@ -38,7 +38,9 @@ concurrency:
 jobs:
   acceptancetest_0:
     # The type of runner that the job will run on
-    runs-on: ubuntu-24.04
+    # Runs on the self-hosted alma10 runners (cern1, ...) to spare the hosted queue;
+    # fork PRs stay on ubuntu-24.04 so outside code never runs on our machines.
+    runs-on: ${{ github.event.pull_request.head.repo.fork && 'ubuntu-24.04' || fromJSON('["self-hosted", "alma10"]') }}
     if: github.event_name == 'push' || github.event.pull_request.head.repo.fork == true
 
     # Steps represent a sequence of tasks that will be executed as part of the job
@@ -67,7 +69,9 @@ jobs:
     #   acceptancetest_contur acceptancetest_60
     #   acceptancetest_uncovered_madevent
     # Each keeps its own steps, run even when an earlier one failed.
-    runs-on: ubuntu-24.04
+    # Runs on the self-hosted alma10 runners (cern1, ...) to spare the hosted queue;
+    # fork PRs stay on ubuntu-24.04 so outside code never runs on our machines.
+    runs-on: ${{ github.event.pull_request.head.repo.fork && 'ubuntu-24.04' || fromJSON('["self-hosted", "alma10"]') }}
     if: github.event_name == 'push' || github.event.pull_request.head.repo.fork == true
     steps:
       - uses: actions/checkout@v4
@@ -94,7 +98,7 @@ jobs:
         if: ${{ !cancelled() }}
         run: |
             #./tests/test_manager.py test_contur_from_file test_rivet_from_file -pA -t0 -l INFO
-            PYTHONPATH=$PYTHONPATH:/home/runner/.cache/HEPtools/contur/python3.10:/home/runner/.cache/HEPTools/rivet/local/lib/python3.10/dist-packages/:/home/runner/.cache/HEPTools/yoda/local/lib/python3.10/dist-packages/ LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/home/runner/.cache/HEPTools/lib ./tests/test_manager.py  test_rivet_from_file -pA -t0 -l INFO
+            PYTHONPATH=$PYTHONPATH:$HOME/.cache/HEPtools/contur/python3.10:$HOME/.cache/HEPTools/rivet/local/lib/python3.10/dist-packages/:$HOME/.cache/HEPTools/yoda/local/lib/python3.10/dist-packages/ LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$HOME/.cache/HEPTools/lib ./tests/test_manager.py  test_rivet_from_file -pA -t0 -l INFO
 
       # ---- acceptancetest_60 ----
       - name: "acceptancetest_60"
@@ -118,7 +122,9 @@ jobs:
     #   acceptancetest_25 acceptancetest_35 acceptancetest_44 acceptancetest_55
     #   acceptancetest_59 acceptancetest_mssm_gogo
     # Each keeps its own steps, run even when an earlier one failed.
-    runs-on: ubuntu-24.04
+    # Runs on the self-hosted alma10 runners (cern1, ...) to spare the hosted queue;
+    # fork PRs stay on ubuntu-24.04 so outside code never runs on our machines.
+    runs-on: ${{ github.event.pull_request.head.repo.fork && 'ubuntu-24.04' || fromJSON('["self-hosted", "alma10"]') }}
     if: github.event_name == 'push' || github.event.pull_request.head.repo.fork == true
     steps:
       - uses: actions/checkout@v4
@@ -192,7 +198,9 @@ jobs:
     #   acceptancetest_density_wpwm acceptancetest_density_decay1
     #   acceptancetest_density_decay2
     # Each keeps its own steps, run even when an earlier one failed.
-    runs-on: ubuntu-24.04
+    # Runs on the self-hosted alma10 runners (cern1, ...) to spare the hosted queue;
+    # fork PRs stay on ubuntu-24.04 so outside code never runs on our machines.
+    runs-on: ${{ github.event.pull_request.head.repo.fork && 'ubuntu-24.04' || fromJSON('["self-hosted", "alma10"]') }}
     if: github.event_name == 'push' || github.event.pull_request.head.repo.fork == true
     steps:
       - uses: actions/checkout@v4
@@ -257,7 +265,9 @@ jobs:
     #   acceptancetest_24 acceptancetest_38 acceptancetest_45 acceptancetest_47
     #   acceptancetest_56 acceptancetest_density_ttbar
     # Each keeps its own steps, run even when an earlier one failed.
-    runs-on: ubuntu-24.04
+    # Runs on the self-hosted alma10 runners (cern1, ...) to spare the hosted queue;
+    # fork PRs stay on ubuntu-24.04 so outside code never runs on our machines.
+    runs-on: ${{ github.event.pull_request.head.repo.fork && 'ubuntu-24.04' || fromJSON('["self-hosted", "alma10"]') }}
     if: github.event_name == 'push' || github.event.pull_request.head.repo.fork == true
     steps:
       - uses: actions/checkout@v4
@@ -326,7 +336,9 @@ jobs:
     # former jobs, run one after the other: acceptancetest_37 acceptancetest_52
     #   acceptancetest_density_interface
     # Each keeps its own steps, run even when an earlier one failed.
-    runs-on: ubuntu-24.04
+    # Runs on the self-hosted alma10 runners (cern1, ...) to spare the hosted queue;
+    # fork PRs stay on ubuntu-24.04 so outside code never runs on our machines.
+    runs-on: ${{ github.event.pull_request.head.repo.fork && 'ubuntu-24.04' || fromJSON('["self-hosted", "alma10"]') }}
     if: github.event_name == 'push' || github.event.pull_request.head.repo.fork == true
     steps:
       - uses: actions/checkout@v4
@@ -395,7 +407,9 @@ jobs:
     #   acceptancetest_46 acceptancetest_49 acceptancetest_contur2
     #   acceptancetest_density_tttbartbar
     # Each keeps its own steps, run even when an earlier one failed.
-    runs-on: ubuntu-24.04
+    # Runs on the self-hosted alma10 runners (cern1, ...) to spare the hosted queue;
+    # fork PRs stay on ubuntu-24.04 so outside code never runs on our machines.
+    runs-on: ${{ github.event.pull_request.head.repo.fork && 'ubuntu-24.04' || fromJSON('["self-hosted", "alma10"]') }}
     if: github.event_name == 'push' || github.event.pull_request.head.repo.fork == true
     steps:
       - uses: actions/checkout@v4
@@ -442,7 +456,7 @@ jobs:
       - name: "acceptancetest_contur2: run the test"
         if: ${{ !cancelled() }}
         run: |
-            PYTHONPATH=$PYTHONPATH:/home/runner/.cache/HEPtools/contur/python3.10 LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/home/runner/.cache/HEPTools/lib ./tests/test_manager.py test_rivet_from_file -pA -t0 -l INFO
+            PYTHONPATH=$PYTHONPATH:$HOME/.cache/HEPtools/contur/python3.10 LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$HOME/.cache/HEPTools/lib ./tests/test_manager.py test_rivet_from_file -pA -t0 -l INFO
 
       # ---- acceptancetest_density_tttbartbar ----
       - name: "acceptancetest_density_tttbartbar"
@@ -460,7 +474,9 @@ jobs:
     # former jobs, run one after the other: acceptancetest_48
     #   acceptancetest_heft acceptancetest_madevent_flavor_zud
     # Each keeps its own steps, run even when an earlier one failed.
-    runs-on: ubuntu-24.04
+    # Runs on the self-hosted alma10 runners (cern1, ...) to spare the hosted queue;
+    # fork PRs stay on ubuntu-24.04 so outside code never runs on our machines.
+    runs-on: ${{ github.event.pull_request.head.repo.fork && 'ubuntu-24.04' || fromJSON('["self-hosted", "alma10"]') }}
     if: github.event_name == 'push' || github.event.pull_request.head.repo.fork == true
     steps:
       - uses: actions/checkout@v4
@@ -494,7 +510,9 @@ jobs:
 
   acceptancetest_53:
     # The type of runner that the job will run on
-    runs-on: ubuntu-24.04
+    # Runs on the self-hosted alma10 runners (cern1, ...) to spare the hosted queue;
+    # fork PRs stay on ubuntu-24.04 so outside code never runs on our machines.
+    runs-on: ${{ github.event.pull_request.head.repo.fork && 'ubuntu-24.04' || fromJSON('["self-hosted", "alma10"]') }}
     if: github.event_name == 'push' || github.event.pull_request.head.repo.fork == true
 
     # Steps represent a sequence of tasks that will be executed as part of the job
@@ -537,7 +555,7 @@ jobs:
       - name: test one of the test test_loop_improved_reweighting
         run: |
             cd $GITHUB_WORKSPACE
-            export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/home/runner/.cache/HEPtools/lhapdf6_py3/lib
+            export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$HOME/.cache/HEPtools/lhapdf6_py3/lib
             export PYTHONPATH=$PYTHONPATH:~/.cache/HEPtools/lhapdf6_py3/lib/python3.12/dist-packages
             export PYTHONPATH=$PYTHONPATH:~/.cache/HEPtools/lhapdf6_py3/lib/python3.10/dist-packages
             ./tests/test_manager.py  test_nlo_reweighting -pA -t0 -l INFO
@@ -547,7 +565,7 @@ jobs:
         if: ${{ !cancelled() }}
         run: |
             cd $GITHUB_WORKSPACE
-            export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/home/runner/.cache/HEPtools/lhapdf6_py3/lib
+            export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$HOME/.cache/HEPtools/lhapdf6_py3/lib
             export PYTHONPATH=$PYTHONPATH:~/.cache/HEPtools/lhapdf6_py3/lib/python3.12/dist-packages
             export PYTHONPATH=$PYTHONPATH:~/.cache/HEPtools/lhapdf6_py3/lib/python3.10/dist-packages
             ./tests/test_manager.py  test_nlo_reweighting_new_parameter -pA -t0 -l INFO
@@ -563,7 +581,9 @@ jobs:
     # former jobs, run one after the other: acceptancetest_103_polarization
     #   acceptancetest_flavor acceptancetest_madevent_vbf_merged_flavor
     # Each keeps its own steps, run even when an earlier one failed.
-    runs-on: ubuntu-24.04
+    # Runs on the self-hosted alma10 runners (cern1, ...) to spare the hosted queue;
+    # fork PRs stay on ubuntu-24.04 so outside code never runs on our machines.
+    runs-on: ${{ github.event.pull_request.head.repo.fork && 'ubuntu-24.04' || fromJSON('["self-hosted", "alma10"]') }}
     if: github.event_name == 'push' || github.event.pull_request.head.repo.fork == true
     steps:
       - uses: actions/checkout@v4

From c10400a041e795dae92c14d9510ca11e777e9406 Mon Sep 17 00:00:00 2001
From: Olivier Mattelaer <olivier.mattelaer@uclouvain.be>
Date: Sat, 24 Oct 2026 17:16:22 +0200
Subject: [PATCH 2/5] selfhosted_heptools: build IREGI/CutTools with a serial
 make

Their makefiles do not declare the Fortran module dependencies, so the
-j$(nproc) inherited from MAKEFLAGS failed on avh_olo_foriregi_dp_box.mod.
---
 .github/actions/selfhosted_heptools/build_heptools.sh | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/.github/actions/selfhosted_heptools/build_heptools.sh b/.github/actions/selfhosted_heptools/build_heptools.sh
index 0fbceab5ec..254753b7c6 100755
--- a/.github/actions/selfhosted_heptools/build_heptools.sh
+++ b/.github/actions/selfhosted_heptools/build_heptools.sh
@@ -47,8 +47,10 @@ build_pythia8() { mg_install "install pythia8"; }
 build_emela()   { mg_install "install eMELA"; }
 build_contur()  { mg_install "install rivet" "install contur"; }
 build_looptools() {
-    (cd "$SRC/vendor/IREGI/src" && make) || return 1
-    (cd "$SRC/vendor/CutTools" && make) || return 1
+    # serial: the IREGI/CutTools makefiles do not declare their Fortran module
+    # dependencies, so a parallel make fails on a missing .mod
+    (cd "$SRC/vendor/IREGI/src" && MAKEFLAGS= make) || return 1
+    (cd "$SRC/vendor/CutTools" && MAKEFLAGS= make) || return 1
     mkdir -p "$HEP/IREGI/src" "$HEP/CutTools/lib"
     cp "$SRC/vendor/IREGI/src/libiregi.a" "$HEP/IREGI/src/"
     cp "$SRC/vendor/CutTools/includects/libcts.a" "$SRC/vendor/CutTools/includects/mpmodule.mod" "$HEP/CutTools/lib"

From 9cad9852b2402b2f4cd1e89d8775176621fced50 Mon Sep 17 00:00:00 2001
From: Olivier Mattelaer <olivier.mattelaer@uclouvain.be>
Date: Sat, 24 Oct 2026 17:29:58 +0200
Subject: [PATCH 3/5] selfhosted_heptools: size the parallel build on the
 available memory

-j$(nproc) got the runner service OOM-killed on the alma10 machines while
building rivet; use one compile per 2 GB of MemAvailable, at most one per core.
---
 .github/actions/selfhosted_heptools/build_heptools.sh | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/.github/actions/selfhosted_heptools/build_heptools.sh b/.github/actions/selfhosted_heptools/build_heptools.sh
index 254753b7c6..da22de741c 100755
--- a/.github/actions/selfhosted_heptools/build_heptools.sh
+++ b/.github/actions/selfhosted_heptools/build_heptools.sh
@@ -6,7 +6,15 @@
 set -u
 HEP="$HOME/.cache/HEPtools"
 CHECK="$GITHUB_WORKSPACE/.github/actions/check_heptools/check_heptools.sh"
-export MAKEFLAGS="-j$(nproc)"
+# The self-hosted machines are short on memory (a -j$(nproc) rivet build got
+# the runner service OOM-killed): one compile per 2 GB available, at most one
+# per core.
+avail_gb=$(awk '/^MemAvailable:/ {print int($2 / 1048576)}' /proc/meminfo)
+jobs=$(( avail_gb / 2 ))
+[ "$jobs" -gt "$(nproc)" ] && jobs=$(nproc)
+[ "$jobs" -lt 1 ] && jobs=1
+export MAKEFLAGS="-j$jobs"
+echo "building with $MAKEFLAGS (${avail_gb} GB available, $(nproc) cores)"
 mkdir -p "$HEP"
 
 # one build at a time per machine, should several runners share this home

From 896f62171419fc2b266151d29cd3072fc196a818 Mon Sep 17 00:00:00 2001
From: Olivier Mattelaer <olivier.mattelaer@uclouvain.be>
Date: Sat, 24 Oct 2026 17:42:25 +0200
Subject: [PATCH 4/5] CI: move only the light IOTests/madevent jobs to the
 alma10 runners

The alma10 machines are small (2 cores, 3.3 GB). Keep on ubuntu-24.04 the
jobs that need rivet/contur or the NLO/loop libraries (IOtest_bundle_2/3,
acceptancetest_0, madevent bundles 1/2/3/6); the moved madevent jobs ask
restore_heptools (new selfhosted_tools input) to build only lhapdf, boost,
pythia8 and eMELA on the machine.
---
 .github/actions/restore_heptools/action.yml   |  9 +++++
 .../actions/selfhosted_heptools/action.yml    |  9 ++++-
 .../selfhosted_heptools/build_heptools.sh     |  5 ++-
 .github/workflows/IOtest.yml                  |  8 +---
 .github/workflows/acceptancetest_madevent.yml | 40 ++++++++++++-------
 5 files changed, 48 insertions(+), 23 deletions(-)

diff --git a/.github/actions/restore_heptools/action.yml b/.github/actions/restore_heptools/action.yml
index c562b0b020..a5267be238 100644
--- a/.github/actions/restore_heptools/action.yml
+++ b/.github/actions/restore_heptools/action.yml
@@ -1,5 +1,12 @@
 name: Restore full heptools cache
 description: Restores heptools from cache and sets MG5 accordingly
+inputs:
+  selfhosted_tools:
+    description: >
+      On a self-hosted runner only: the components to build on the machine when
+      missing (see selfhosted_heptools). Ignored on GitHub-hosted runners.
+    required: false
+    default: 'lhapdf boost pythia8 emela contur looptools'
 
 runs:
   using: composite
@@ -55,6 +62,8 @@ runs:
     - name: build HEPTools on this machine
       if: runner.environment == 'self-hosted'
       uses: ./.github/actions/selfhosted_heptools
+      with:
+        tools: ${{ inputs.selfhosted_tools }}
 
     # setup other environment of previous level of cache
     # try to use their cache if previous cache failed or content is incomplete
diff --git a/.github/actions/selfhosted_heptools/action.yml b/.github/actions/selfhosted_heptools/action.yml
index c8af95470d..16d3e674d5 100644
--- a/.github/actions/selfhosted_heptools/action.yml
+++ b/.github/actions/selfhosted_heptools/action.yml
@@ -5,9 +5,16 @@ description: >
   with paths baked in for, the ubuntu image) each machine builds the missing
   components itself, once, the first time a job needs them. A component that
   fails to build only warns: the tests that need it then fail, the others run.
+inputs:
+  tools:
+    description: 'Components to build when missing, among lhapdf boost pythia8 emela contur looptools'
+    required: false
+    default: 'lhapdf boost pythia8 emela contur looptools'
 runs:
   using: composite
   steps:
     - name: Build the missing HEPTools components
       shell: bash
-      run: bash "${{ github.action_path }}/build_heptools.sh"
+      env:
+        HEPTOOLS_BUILD: ${{ inputs.tools }}
+      run: bash "${{ github.action_path }}/build_heptools.sh" $HEPTOOLS_BUILD
diff --git a/.github/actions/selfhosted_heptools/build_heptools.sh b/.github/actions/selfhosted_heptools/build_heptools.sh
index da22de741c..3f6da3855a 100755
--- a/.github/actions/selfhosted_heptools/build_heptools.sh
+++ b/.github/actions/selfhosted_heptools/build_heptools.sh
@@ -1,5 +1,6 @@
 #!/usr/bin/env bash
-# Build into ~/.cache/HEPtools every HEPTools component that check_heptools
+# usage: build_heptools.sh [component ...]   (default: all of them)
+# Build into ~/.cache/HEPtools every requested HEPTools component that check_heptools
 # does not find complete there, with the same install commands as the
 # warm_cache.yml jobs. Runs from a pristine copy of the checked-out tree, so
 # the job's own tree is left as checked out.
@@ -66,7 +67,9 @@ build_looptools() {
 }
 
 # dependency order: emela needs boost, contur needs pythia8 (hepmc)
+requested=" ${*:-lhapdf boost pythia8 emela contur looptools} "
 for tool in lhapdf boost pythia8 emela contur looptools; do
+    [[ "$requested" == *" $tool "* ]] || continue
     if complete "$tool"; then
         echo "$tool: already built on $RUNNER_NAME"
         continue
diff --git a/.github/workflows/IOtest.yml b/.github/workflows/IOtest.yml
index b22e12dcf0..5deeaebc14 100644
--- a/.github/workflows/IOtest.yml
+++ b/.github/workflows/IOtest.yml
@@ -120,9 +120,7 @@ jobs:
     # former jobs, run one after the other: IOtest_acceptance_proc
     #   IOtest_matchbox
     # Each keeps its own steps, run even when an earlier one failed.
-    # Runs on the self-hosted alma10 runners (cern1, ...) to spare the hosted queue;
-    # fork PRs stay on ubuntu-24.04 so outside code never runs on our machines.
-    runs-on: ${{ github.event.pull_request.head.repo.fork && 'ubuntu-24.04' || fromJSON('["self-hosted", "alma10"]') }}
+    runs-on: ubuntu-24.04
     steps:
       - uses: actions/checkout@v4
       - uses: ./.github/actions/checkout_mg5
@@ -153,9 +151,7 @@ jobs:
   IOtest_bundle_3:
     # former jobs, run one after the other: IOtest_TIR IOtest_loop_induced
     # Each keeps its own steps, run even when an earlier one failed.
-    # Runs on the self-hosted alma10 runners (cern1, ...) to spare the hosted queue;
-    # fork PRs stay on ubuntu-24.04 so outside code never runs on our machines.
-    runs-on: ${{ github.event.pull_request.head.repo.fork && 'ubuntu-24.04' || fromJSON('["self-hosted", "alma10"]') }}
+    runs-on: ubuntu-24.04
     steps:
       - uses: actions/checkout@v4
       - uses: ./.github/actions/checkout_mg5
diff --git a/.github/workflows/acceptancetest_madevent.yml b/.github/workflows/acceptancetest_madevent.yml
index 64f39f2f37..64edc413d1 100644
--- a/.github/workflows/acceptancetest_madevent.yml
+++ b/.github/workflows/acceptancetest_madevent.yml
@@ -38,9 +38,7 @@ concurrency:
 jobs:
   acceptancetest_0:
     # The type of runner that the job will run on
-    # Runs on the self-hosted alma10 runners (cern1, ...) to spare the hosted queue;
-    # fork PRs stay on ubuntu-24.04 so outside code never runs on our machines.
-    runs-on: ${{ github.event.pull_request.head.repo.fork && 'ubuntu-24.04' || fromJSON('["self-hosted", "alma10"]') }}
+    runs-on: ubuntu-24.04
     if: github.event_name == 'push' || github.event.pull_request.head.repo.fork == true
 
     # Steps represent a sequence of tasks that will be executed as part of the job
@@ -69,9 +67,7 @@ jobs:
     #   acceptancetest_contur acceptancetest_60
     #   acceptancetest_uncovered_madevent
     # Each keeps its own steps, run even when an earlier one failed.
-    # Runs on the self-hosted alma10 runners (cern1, ...) to spare the hosted queue;
-    # fork PRs stay on ubuntu-24.04 so outside code never runs on our machines.
-    runs-on: ${{ github.event.pull_request.head.repo.fork && 'ubuntu-24.04' || fromJSON('["self-hosted", "alma10"]') }}
+    runs-on: ubuntu-24.04
     if: github.event_name == 'push' || github.event.pull_request.head.repo.fork == true
     steps:
       - uses: actions/checkout@v4
@@ -122,9 +118,7 @@ jobs:
     #   acceptancetest_25 acceptancetest_35 acceptancetest_44 acceptancetest_55
     #   acceptancetest_59 acceptancetest_mssm_gogo
     # Each keeps its own steps, run even when an earlier one failed.
-    # Runs on the self-hosted alma10 runners (cern1, ...) to spare the hosted queue;
-    # fork PRs stay on ubuntu-24.04 so outside code never runs on our machines.
-    runs-on: ${{ github.event.pull_request.head.repo.fork && 'ubuntu-24.04' || fromJSON('["self-hosted", "alma10"]') }}
+    runs-on: ubuntu-24.04
     if: github.event_name == 'push' || github.event.pull_request.head.repo.fork == true
     steps:
       - uses: actions/checkout@v4
@@ -198,9 +192,7 @@ jobs:
     #   acceptancetest_density_wpwm acceptancetest_density_decay1
     #   acceptancetest_density_decay2
     # Each keeps its own steps, run even when an earlier one failed.
-    # Runs on the self-hosted alma10 runners (cern1, ...) to spare the hosted queue;
-    # fork PRs stay on ubuntu-24.04 so outside code never runs on our machines.
-    runs-on: ${{ github.event.pull_request.head.repo.fork && 'ubuntu-24.04' || fromJSON('["self-hosted", "alma10"]') }}
+    runs-on: ubuntu-24.04
     if: github.event_name == 'push' || github.event.pull_request.head.repo.fork == true
     steps:
       - uses: actions/checkout@v4
@@ -273,6 +265,10 @@ jobs:
       - uses: actions/checkout@v4
       - uses: ./.github/actions/checkout_mg5
       - uses: ./.github/actions/restore_heptools
+        # only what these tests need: rivet/contur and the loop libraries are
+        # not built on the (small) self-hosted machines
+        with:
+          selfhosted_tools: lhapdf boost pythia8 emela
       - uses: ./.github/actions/restore-pip-cache
 
       # ---- acceptancetest_20 ----
@@ -345,6 +341,10 @@ jobs:
       - uses: ./.github/actions/checkout_mg5
       - uses: ./.github/actions/restore-pip-cache
       - uses: ./.github/actions/restore_heptools
+        # only what these tests need: rivet/contur and the loop libraries are
+        # not built on the (small) self-hosted machines
+        with:
+          selfhosted_tools: lhapdf boost pythia8 emela
 
       # ---- acceptancetest_37 ----
       - name: "acceptancetest_37"
@@ -407,9 +407,7 @@ jobs:
     #   acceptancetest_46 acceptancetest_49 acceptancetest_contur2
     #   acceptancetest_density_tttbartbar
     # Each keeps its own steps, run even when an earlier one failed.
-    # Runs on the self-hosted alma10 runners (cern1, ...) to spare the hosted queue;
-    # fork PRs stay on ubuntu-24.04 so outside code never runs on our machines.
-    runs-on: ${{ github.event.pull_request.head.repo.fork && 'ubuntu-24.04' || fromJSON('["self-hosted", "alma10"]') }}
+    runs-on: ubuntu-24.04
     if: github.event_name == 'push' || github.event.pull_request.head.repo.fork == true
     steps:
       - uses: actions/checkout@v4
@@ -482,6 +480,10 @@ jobs:
       - uses: actions/checkout@v4
       - uses: ./.github/actions/checkout_mg5
       - uses: ./.github/actions/restore_heptools
+        # only what these tests need: rivet/contur and the loop libraries are
+        # not built on the (small) self-hosted machines
+        with:
+          selfhosted_tools: lhapdf boost pythia8 emela
 
       # ---- acceptancetest_48 ----
       - name: "acceptancetest_48"
@@ -521,6 +523,10 @@ jobs:
       - uses: actions/checkout@v4
       - uses: ./.github/actions/checkout_mg5
       - uses: ./.github/actions/restore_heptools
+        # only what these tests need: rivet/contur and the loop libraries are
+        # not built on the (small) self-hosted machines
+        with:
+          selfhosted_tools: lhapdf boost pythia8 emela
       - uses: ./.github/actions/restore-pip-cache
       - uses: ./.github/actions/restore_ufomodel
 
@@ -589,6 +595,10 @@ jobs:
       - uses: actions/checkout@v4
       - uses: ./.github/actions/checkout_mg5
       - uses: ./.github/actions/restore_heptools
+        # only what these tests need: rivet/contur and the loop libraries are
+        # not built on the (small) self-hosted machines
+        with:
+          selfhosted_tools: lhapdf boost pythia8 emela
 
       # ---- acceptancetest_103_polarization ----
       - name: "acceptancetest_103_polarization"

From 904543d5bed1a5a537b37f19a989cd305d283829 Mon Sep 17 00:00:00 2001
From: Olivier Mattelaer <olivier.mattelaer@uclouvain.be>
Date: Sat, 24 Oct 2026 17:48:51 +0200
Subject: [PATCH 5/5] CI: keep the madevent acceptance tests on ubuntu; only
 IOTests use alma10

Only IOtest_bundle_1, IOtest_loop_sqso and IOtest_gnuplot run on the alma10
runners, and none of them needs HEPTools, so the per-machine HEPTools build
(selfhosted_heptools) and the restore_heptools changes are dropped again.
---
 .github/actions/restore_heptools/action.yml   | 28 ++----
 .../restore_heptools_contur/action.yml        | 27 ++----
 .../actions/restore_heptools_emela/action.yml |  2 +-
 .../restore_heptools_lhapdf/action.yml        | 27 ++----
 .../restore_heptools_looptools/action.yml     |  4 +-
 .../restore_heptools_pythia8/action.yml       |  4 +-
 .../actions/selfhosted_heptools/action.yml    | 20 -----
 .../selfhosted_heptools/build_heptools.sh     | 85 -------------------
 .github/workflows/acceptancetest_madevent.yml | 48 ++---------
 9 files changed, 35 insertions(+), 210 deletions(-)
 delete mode 100644 .github/actions/selfhosted_heptools/action.yml
 delete mode 100755 .github/actions/selfhosted_heptools/build_heptools.sh

diff --git a/.github/actions/restore_heptools/action.yml b/.github/actions/restore_heptools/action.yml
index a5267be238..eab077c740 100644
--- a/.github/actions/restore_heptools/action.yml
+++ b/.github/actions/restore_heptools/action.yml
@@ -1,12 +1,5 @@
 name: Restore full heptools cache
 description: Restores heptools from cache and sets MG5 accordingly
-inputs:
-  selfhosted_tools:
-    description: >
-      On a self-hosted runner only: the components to build on the machine when
-      missing (see selfhosted_heptools). Ignored on GitHub-hosted runners.
-    required: false
-    default: 'lhapdf boost pythia8 emela contur looptools'
 
 runs:
   using: composite
@@ -31,7 +24,6 @@ runs:
     # every restore_heptools_* action.
     - name: restore full cache
       id: heptools-cache
-      if: runner.environment != 'self-hosted'
       uses: actions/cache/restore@v5
       with:
         path: ~/.cache/HEPtools
@@ -57,31 +49,23 @@ runs:
         tools: lhapdf boost pythia8 emela contur looptools
         mode: report
 
-    # A self-hosted runner does not use the GitHub caches at all: it keeps its
-    # own ~/.cache/HEPtools and builds what is missing there (once per machine).
-    - name: build HEPTools on this machine
-      if: runner.environment == 'self-hosted'
-      uses: ./.github/actions/selfhosted_heptools
-      with:
-        tools: ${{ inputs.selfhosted_tools }}
-
     # setup other environment of previous level of cache
     # try to use their cache if previous cache failed or content is incomplete
     - uses: ./.github/actions/restore_heptools_lhapdf
       with:
-        setup_only: ${{ runner.environment == 'self-hosted' || (steps.heptools-cache.outputs.cache-matched-key != '' && steps.validate-cache.outputs.valid == 'true') }}
+        setup_only: ${{ steps.heptools-cache.outputs.cache-matched-key != '' && steps.validate-cache.outputs.valid == 'true' }}
     - uses: ./.github/actions/restore_heptools_boost
       with:
-        setup_only: ${{ runner.environment == 'self-hosted' || (steps.heptools-cache.outputs.cache-matched-key != '' && steps.validate-cache.outputs.valid == 'true') }}
+        setup_only: ${{ steps.heptools-cache.outputs.cache-matched-key != '' && steps.validate-cache.outputs.valid == 'true' }}
     - uses: ./.github/actions/restore_heptools_pythia8
       with:
-        setup_only: ${{ runner.environment == 'self-hosted' || (steps.heptools-cache.outputs.cache-matched-key != '' && steps.validate-cache.outputs.valid == 'true') }}
+        setup_only: ${{ steps.heptools-cache.outputs.cache-matched-key != '' && steps.validate-cache.outputs.valid == 'true' }}
     - uses: ./.github/actions/restore_heptools_emela
       with:
-        setup_only: ${{ runner.environment == 'self-hosted' || (steps.heptools-cache.outputs.cache-matched-key != '' && steps.validate-cache.outputs.valid == 'true') }}
+        setup_only: ${{ steps.heptools-cache.outputs.cache-matched-key != '' && steps.validate-cache.outputs.valid == 'true' }}
     - uses: ./.github/actions/restore_heptools_contur
       with:
-        setup_only: ${{ runner.environment == 'self-hosted' || (steps.heptools-cache.outputs.cache-matched-key != '' && steps.validate-cache.outputs.valid == 'true') }}
+        setup_only: ${{ steps.heptools-cache.outputs.cache-matched-key != '' && steps.validate-cache.outputs.valid == 'true' }}
     - uses: ./.github/actions/restore_heptools_looptools
       with:
-        setup_only: ${{ runner.environment == 'self-hosted' || (steps.heptools-cache.outputs.cache-matched-key != '' && steps.validate-cache.outputs.valid == 'true') }}
+        setup_only: ${{ steps.heptools-cache.outputs.cache-matched-key != '' && steps.validate-cache.outputs.valid == 'true' }}
diff --git a/.github/actions/restore_heptools_contur/action.yml b/.github/actions/restore_heptools_contur/action.yml
index 88520df3ad..de42f53f9c 100644
--- a/.github/actions/restore_heptools_contur/action.yml
+++ b/.github/actions/restore_heptools_contur/action.yml
@@ -33,10 +33,10 @@ runs:
 
     - run: |
         cd $GITHUB_WORKSPACE
-        echo "hepmc3_path = $HOME/.cache/HEPtools/hepmc3" >>  input/mg7_configuration.txt
-        echo "rivet_path = $HOME/.cache/HEPtools/rivet" >>  input/mg7_configuration.txt
-        echo "yoda_path = $HOME/.cache/HEPtools/yoda" >>  input/mg7_configuration.txt
-        echo "contur_path = $HOME/.cache/HEPtools/contur" >>  input/mg7_configuration.txt
+        echo "hepmc3_path = /home/runner/.cache/HEPtools/hepmc3" >>  input/mg7_configuration.txt
+        echo "rivet_path = /home/runner/.cache/HEPtools/rivet" >>  input/mg7_configuration.txt
+        echo "yoda_path = /home/runner/.cache/HEPtools/yoda" >>  input/mg7_configuration.txt
+        echo "contur_path = /home/runner/.cache/HEPtools/contur" >>  input/mg7_configuration.txt
         # Only point MG5 at fastjet if it is really there.  The cache restore
         # above is best-effort (fail-on-cache-miss is false, and warm_cache
         # deletes the contur/heptools caches ~30 min before it re-saves them,
@@ -46,7 +46,7 @@ runs:
         # fastjet/ClusterSequence.hh.  Without the line MG5 uses fjcore, which
         # is a working fallback: the contur/rivet jobs still fail, loudly and on
         # their own, but the numbered acceptance jobs no longer fail with them.
-        FJ=$HOME/.cache/HEPtools/fastjet/bin/fastjet-config
+        FJ=/home/runner/.cache/HEPtools/fastjet/bin/fastjet-config
         if [ -x "$FJ" ]; then
           echo "fastjet = $FJ" >>  input/mg7_configuration.txt
         else
@@ -57,24 +57,11 @@ runs:
     - name: set pythonpath for ubuntu22
       if: ${{ env.HEPTOOLS_IMAGE == 'ubuntu22' }}
       run: |
-          echo "PYTHONPATH=$PYTHONPATH:$HOME/.cache/HEPtools/contur/python3.10/:$HOME/.cache/HEPtools/rivet/python3.10/:$HOME/.cache/HEPtools/rivet/local/python3.10/" >> $GITHUB_ENV
+          echo "PYTHONPATH=$PYTHONPATH:/home/runner/.cache/HEPtools/contur/python3.10/:/home/runner/.cache/HEPtools/rivet/python3.10/:/home/runner/.cache/HEPtools/rivet/local/python3.10/" >> $GITHUB_ENV
       shell: bash
 
     - name: set pythonpath for ubuntu24
       if: ${{ env.HEPTOOLS_IMAGE == 'ubuntu24' }}
       run: |
-          echo "PYTHONPATH=$PYTHONPATH:$HOME/.cache/HEPtools/contur/python3.12/:$HOME/.cache/HEPtools/rivet/python3.12/:$HOME/.cache/HEPtools/rivet/local/python3.10/" >> $GITHUB_ENV
-      shell: bash
-    # any other image (a self-hosted runner, where ImageOS is unset): take the
-    # python modules wherever this machine's build put them
-    - name: set pythonpath for other images
-      if: ${{ env.HEPTOOLS_IMAGE != 'ubuntu22' && env.HEPTOOLS_IMAGE != 'ubuntu24' }}
-      run: |
-        P=$PYTHONPATH
-        for d in $HOME/.cache/HEPtools/contur/python3* $HOME/.cache/HEPtools/rivet/python3* \
-                 $HOME/.cache/HEPtools/rivet/local/python3* \
-                 $HOME/.cache/HEPtools/{rivet,yoda}/{,local/}lib*/python3*/*-packages; do
-          [ -d "$d" ] && P=$P:$d
-        done
-        echo "PYTHONPATH=$P" >> $GITHUB_ENV
+          echo "PYTHONPATH=$PYTHONPATH:/home/runner/.cache/HEPtools/contur/python3.12/:/home/runner/.cache/HEPtools/rivet/python3.12/:/home/runner/.cache/HEPtools/rivet/local/python3.10/" >> $GITHUB_ENV
       shell: bash
diff --git a/.github/actions/restore_heptools_emela/action.yml b/.github/actions/restore_heptools_emela/action.yml
index 3e0a19043c..5df5ee0645 100644
--- a/.github/actions/restore_heptools_emela/action.yml
+++ b/.github/actions/restore_heptools_emela/action.yml
@@ -34,5 +34,5 @@ runs:
 
     - run: |
         cd $GITHUB_WORKSPACE
-        echo "eMELA = $HOME/.cache/HEPtools/bin/eMELA-config" >>       input/mg7_configuration.txt
+        echo "eMELA = /home/runner/.cache/HEPtools/bin/eMELA-config" >>       input/mg7_configuration.txt
       shell: bash
diff --git a/.github/actions/restore_heptools_lhapdf/action.yml b/.github/actions/restore_heptools_lhapdf/action.yml
index e000605641..83b0379839 100644
--- a/.github/actions/restore_heptools_lhapdf/action.yml
+++ b/.github/actions/restore_heptools_lhapdf/action.yml
@@ -36,23 +36,23 @@ runs:
 
     - run: |
         cd $GITHUB_WORKSPACE
-        echo "heptools_install_dir=$HOME/.cache/HEPtools" >> input/mg7_configuration.txt
-        echo "lhapdf = $HOME/.cache/HEPtools/bin/lhapdf-config" >>       input/mg7_configuration.txt
-        echo "lhapdf_py3 = $HOME/.cache/HEPtools/bin/lhapdf-config" >>       input/mg7_configuration.txt
-        echo "LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$HOME/.cache/HEPtools/lhapdf6_py3//lib" >> $GITHUB_ENV
-        echo "LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$HOME/.cache/HEPtools/lib" >> $GITHUB_ENV
+        echo "heptools_install_dir=/home/runner/.cache/HEPtools" >> input/mg7_configuration.txt
+        echo "lhapdf = /home/runner/.cache/HEPtools/bin/lhapdf-config" >>       input/mg7_configuration.txt
+        echo "lhapdf_py3 = /home/runner/.cache/HEPtools/bin/lhapdf-config" >>       input/mg7_configuration.txt
+        echo "LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/home/runner/.cache/HEPtools/lhapdf6_py3//lib" >> $GITHUB_ENV
+        echo "LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/home/runner/.cache/HEPtools/lib" >> $GITHUB_ENV
       shell: bash
 
     - name: set pythonpath for ubuntu22
       if: ${{ env.HEPTOOLS_IMAGE == 'ubuntu22' }}
       run: |
-        echo "PYTHONPATH=$PYTHONPATH:$HOME/.cache/HEPtools/lhapdf6_py3/lib/python3.10/dist-packages" >> $GITHUB_ENV
+        echo "PYTHONPATH=$PYTHONPATH:/home/runner/.cache/HEPtools/lhapdf6_py3/lib/python3.10/dist-packages" >> $GITHUB_ENV
       shell: bash 
 
     - name: set pythonpath for ubuntu24
       if: ${{ env.HEPTOOLS_IMAGE == 'ubuntu24' }}
       run: |
-        echo "PYTHONPATH=$PYTHONPATH:$HOME/.cache/HEPtools/lhapdf6_py3/lib/python3.12/dist-packages" >> $GITHUB_ENV
+        echo "PYTHONPATH=$PYTHONPATH:/home/runner/.cache/HEPtools/lhapdf6_py3/lib/python3.12/dist-packages" >> $GITHUB_ENV
       shell: bash
 
     # The run_card default PDF sets: NNPDF40_lo_as_01180 (mg7 [beam] pdf and the
@@ -63,20 +63,9 @@ runs:
     # on the set being present and would all self-skip (test_manager.py counts a
     # skip as a failure). Fetching them here is a no-op once the cache carries
     # them. Non-fatal on failure: the tests skip as they did before.
-    # any other image (a self-hosted runner, where ImageOS is unset): take the
-    # python bindings wherever this machine's build put them
-    - name: set pythonpath for other images
-      if: ${{ env.HEPTOOLS_IMAGE != 'ubuntu22' && env.HEPTOOLS_IMAGE != 'ubuntu24' }}
-      run: |
-        P=$PYTHONPATH
-        for d in $HOME/.cache/HEPtools/lhapdf6_py3/lib*/python3*/*-packages; do
-          [ -d "$d" ] && P=$P:$d
-        done
-        echo "PYTHONPATH=$P" >> $GITHUB_ENV
-      shell: bash
     - name: ensure the default PDF sets are present
       run: |
-        DATADIR=$HOME/.cache/HEPtools/lhapdf6_py3/share/LHAPDF
+        DATADIR=/home/runner/.cache/HEPtools/lhapdf6_py3/share/LHAPDF
         for SET in NNPDF40_lo_as_01180 NNPDF40_nlo_as_01180 NNPDF40_nlo_as_01180_nf_4; do
           if [ -d "$DATADIR" ] && [ ! -d "$DATADIR/$SET" ]; then
             ( cd "$DATADIR" \
diff --git a/.github/actions/restore_heptools_looptools/action.yml b/.github/actions/restore_heptools_looptools/action.yml
index 7d7dddde44..157d381b32 100644
--- a/.github/actions/restore_heptools_looptools/action.yml
+++ b/.github/actions/restore_heptools_looptools/action.yml
@@ -28,6 +28,6 @@ runs:
     # this ignore cuttools/iregi cache ... ok but we should try to fix that
     - run: |
         cd $GITHUB_WORKSPACE
-        echo "ninja = $HOME/.cache/HEPtools/ninja/lib" >>  input/mg7_configuration.txt
-        echo "collier = $HOME/.cache/HEPtools/collier" >>  input/mg7_configuration.txt
+        echo "ninja = /home/runner/.cache/HEPtools/ninja/lib" >>  input/mg7_configuration.txt
+        echo "collier = /home/runner/.cache/HEPtools/collier" >>  input/mg7_configuration.txt
       shell: bash
diff --git a/.github/actions/restore_heptools_pythia8/action.yml b/.github/actions/restore_heptools_pythia8/action.yml
index 921c7570c8..1b01937b07 100644
--- a/.github/actions/restore_heptools_pythia8/action.yml
+++ b/.github/actions/restore_heptools_pythia8/action.yml
@@ -34,6 +34,6 @@ runs:
 
     - run: |
         cd $GITHUB_WORKSPACE
-        echo "pythia8_path = $HOME/.cache/HEPtools/pythia8" >>  input/mg7_configuration.txt
-        echo "hepmc_path = $HOME/.cache/HEPtools/hepmc" >>  input/mg7_configuration.txt
+        echo "pythia8_path = /home/runner/.cache/HEPtools/pythia8" >>  input/mg7_configuration.txt
+        echo "hepmc_path = /home/runner/.cache/HEPtools/hepmc" >>  input/mg7_configuration.txt
       shell: bash
diff --git a/.github/actions/selfhosted_heptools/action.yml b/.github/actions/selfhosted_heptools/action.yml
deleted file mode 100644
index 16d3e674d5..0000000000
--- a/.github/actions/selfhosted_heptools/action.yml
+++ /dev/null
@@ -1,20 +0,0 @@
-name: Build HEPTools on a self-hosted runner
-description: >
-  A self-hosted runner keeps ~/.cache/HEPtools on its own disk from one job to
-  the next, so instead of the GitHub caches (built by warm_cache.yml on, and
-  with paths baked in for, the ubuntu image) each machine builds the missing
-  components itself, once, the first time a job needs them. A component that
-  fails to build only warns: the tests that need it then fail, the others run.
-inputs:
-  tools:
-    description: 'Components to build when missing, among lhapdf boost pythia8 emela contur looptools'
-    required: false
-    default: 'lhapdf boost pythia8 emela contur looptools'
-runs:
-  using: composite
-  steps:
-    - name: Build the missing HEPTools components
-      shell: bash
-      env:
-        HEPTOOLS_BUILD: ${{ inputs.tools }}
-      run: bash "${{ github.action_path }}/build_heptools.sh" $HEPTOOLS_BUILD
diff --git a/.github/actions/selfhosted_heptools/build_heptools.sh b/.github/actions/selfhosted_heptools/build_heptools.sh
deleted file mode 100755
index 3f6da3855a..0000000000
--- a/.github/actions/selfhosted_heptools/build_heptools.sh
+++ /dev/null
@@ -1,85 +0,0 @@
-#!/usr/bin/env bash
-# usage: build_heptools.sh [component ...]   (default: all of them)
-# Build into ~/.cache/HEPtools every requested HEPTools component that check_heptools
-# does not find complete there, with the same install commands as the
-# warm_cache.yml jobs. Runs from a pristine copy of the checked-out tree, so
-# the job's own tree is left as checked out.
-set -u
-HEP="$HOME/.cache/HEPtools"
-CHECK="$GITHUB_WORKSPACE/.github/actions/check_heptools/check_heptools.sh"
-# The self-hosted machines are short on memory (a -j$(nproc) rivet build got
-# the runner service OOM-killed): one compile per 2 GB available, at most one
-# per core.
-avail_gb=$(awk '/^MemAvailable:/ {print int($2 / 1048576)}' /proc/meminfo)
-jobs=$(( avail_gb / 2 ))
-[ "$jobs" -gt "$(nproc)" ] && jobs=$(nproc)
-[ "$jobs" -lt 1 ] && jobs=1
-export MAKEFLAGS="-j$jobs"
-echo "building with $MAKEFLAGS (${avail_gb} GB available, $(nproc) cores)"
-mkdir -p "$HEP"
-
-# one build at a time per machine, should several runners share this home
-exec 9> "$HEP.lock"
-flock 9
-
-complete() {
-    HEPTOOLS_PREFIX="$HEP" CHECK_MODE=fatal GITHUB_OUTPUT= bash "$CHECK" "$1" > /dev/null 2>&1
-}
-
-SRC=""
-prepare_src() {
-    [ -n "$SRC" ] && return
-    SRC=$(mktemp -d "${RUNNER_TEMP:-/tmp}/heptools-src.XXXXXX")
-    git -C "$GITHUB_WORKSPACE" archive HEAD | tar -x -C "$SRC"
-    cp "$SRC/input/.mg7_configuration_default.txt" "$SRC/input/mg7_configuration.txt"
-    echo "heptools_install_dir=$HEP" >> "$SRC/input/mg7_configuration.txt"
-    cp "$SRC/Template/LO/Source/.make_opts" "$SRC/Template/LO/Source/make_opts"
-}
-
-mg_install() {
-    printf '%s\n' "$@" > "$SRC/cmd"
-    (cd "$SRC" && ./bin/madgraph cmd)
-}
-
-build_lhapdf() {
-    mg_install "install lhapdf6"
-    cd "$HEP/lhapdf6_py3/share/LHAPDF" || return 1
-    for SET in NNPDF23_nlo_as_0118_qed cteq6l1 NNPDF40_lo_as_01180 NNPDF40_nlo_as_01180 \
-               NNPDF40_nlo_as_01180_nf_4 NNPDF40MC_lo_as_01180 NNPDF23_lo_as_0130_qed; do
-        [ -d "$SET" ] && continue
-        wget -q "https://lhapdfsets.web.cern.ch/current/$SET.tar.gz" \
-            && tar -xzpf "$SET.tar.gz" && rm -f "$SET.tar.gz"
-    done
-}
-build_boost()   { mg_install "install boost"; }
-build_pythia8() { mg_install "install pythia8"; }
-build_emela()   { mg_install "install eMELA"; }
-build_contur()  { mg_install "install rivet" "install contur"; }
-build_looptools() {
-    # serial: the IREGI/CutTools makefiles do not declare their Fortran module
-    # dependencies, so a parallel make fails on a missing .mod
-    (cd "$SRC/vendor/IREGI/src" && MAKEFLAGS= make) || return 1
-    (cd "$SRC/vendor/CutTools" && MAKEFLAGS= make) || return 1
-    mkdir -p "$HEP/IREGI/src" "$HEP/CutTools/lib"
-    cp "$SRC/vendor/IREGI/src/libiregi.a" "$HEP/IREGI/src/"
-    cp "$SRC/vendor/CutTools/includects/libcts.a" "$SRC/vendor/CutTools/includects/mpmodule.mod" "$HEP/CutTools/lib"
-    mg_install "install collier" "install ninja"
-}
-
-# dependency order: emela needs boost, contur needs pythia8 (hepmc)
-requested=" ${*:-lhapdf boost pythia8 emela contur looptools} "
-for tool in lhapdf boost pythia8 emela contur looptools; do
-    [[ "$requested" == *" $tool "* ]] || continue
-    if complete "$tool"; then
-        echo "$tool: already built on $RUNNER_NAME"
-        continue
-    fi
-    echo "::group::building $tool on $RUNNER_NAME (first use on this machine)"
-    prepare_src
-    ( "build_$tool" )
-    echo "::endgroup::"
-    complete "$tool" || echo "::warning::HEPTools $tool could not be built on $RUNNER_NAME"
-done
-
-[ -n "$SRC" ] && rm -rf "$SRC"
-exit 0
diff --git a/.github/workflows/acceptancetest_madevent.yml b/.github/workflows/acceptancetest_madevent.yml
index 64edc413d1..68164e7016 100644
--- a/.github/workflows/acceptancetest_madevent.yml
+++ b/.github/workflows/acceptancetest_madevent.yml
@@ -94,7 +94,7 @@ jobs:
         if: ${{ !cancelled() }}
         run: |
             #./tests/test_manager.py test_contur_from_file test_rivet_from_file -pA -t0 -l INFO
-            PYTHONPATH=$PYTHONPATH:$HOME/.cache/HEPtools/contur/python3.10:$HOME/.cache/HEPTools/rivet/local/lib/python3.10/dist-packages/:$HOME/.cache/HEPTools/yoda/local/lib/python3.10/dist-packages/ LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$HOME/.cache/HEPTools/lib ./tests/test_manager.py  test_rivet_from_file -pA -t0 -l INFO
+            PYTHONPATH=$PYTHONPATH:/home/runner/.cache/HEPtools/contur/python3.10:/home/runner/.cache/HEPTools/rivet/local/lib/python3.10/dist-packages/:/home/runner/.cache/HEPTools/yoda/local/lib/python3.10/dist-packages/ LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/home/runner/.cache/HEPTools/lib ./tests/test_manager.py  test_rivet_from_file -pA -t0 -l INFO
 
       # ---- acceptancetest_60 ----
       - name: "acceptancetest_60"
@@ -257,18 +257,12 @@ jobs:
     #   acceptancetest_24 acceptancetest_38 acceptancetest_45 acceptancetest_47
     #   acceptancetest_56 acceptancetest_density_ttbar
     # Each keeps its own steps, run even when an earlier one failed.
-    # Runs on the self-hosted alma10 runners (cern1, ...) to spare the hosted queue;
-    # fork PRs stay on ubuntu-24.04 so outside code never runs on our machines.
-    runs-on: ${{ github.event.pull_request.head.repo.fork && 'ubuntu-24.04' || fromJSON('["self-hosted", "alma10"]') }}
+    runs-on: ubuntu-24.04
     if: github.event_name == 'push' || github.event.pull_request.head.repo.fork == true
     steps:
       - uses: actions/checkout@v4
       - uses: ./.github/actions/checkout_mg5
       - uses: ./.github/actions/restore_heptools
-        # only what these tests need: rivet/contur and the loop libraries are
-        # not built on the (small) self-hosted machines
-        with:
-          selfhosted_tools: lhapdf boost pythia8 emela
       - uses: ./.github/actions/restore-pip-cache
 
       # ---- acceptancetest_20 ----
@@ -332,19 +326,13 @@ jobs:
     # former jobs, run one after the other: acceptancetest_37 acceptancetest_52
     #   acceptancetest_density_interface
     # Each keeps its own steps, run even when an earlier one failed.
-    # Runs on the self-hosted alma10 runners (cern1, ...) to spare the hosted queue;
-    # fork PRs stay on ubuntu-24.04 so outside code never runs on our machines.
-    runs-on: ${{ github.event.pull_request.head.repo.fork && 'ubuntu-24.04' || fromJSON('["self-hosted", "alma10"]') }}
+    runs-on: ubuntu-24.04
     if: github.event_name == 'push' || github.event.pull_request.head.repo.fork == true
     steps:
       - uses: actions/checkout@v4
       - uses: ./.github/actions/checkout_mg5
       - uses: ./.github/actions/restore-pip-cache
       - uses: ./.github/actions/restore_heptools
-        # only what these tests need: rivet/contur and the loop libraries are
-        # not built on the (small) self-hosted machines
-        with:
-          selfhosted_tools: lhapdf boost pythia8 emela
 
       # ---- acceptancetest_37 ----
       - name: "acceptancetest_37"
@@ -454,7 +442,7 @@ jobs:
       - name: "acceptancetest_contur2: run the test"
         if: ${{ !cancelled() }}
         run: |
-            PYTHONPATH=$PYTHONPATH:$HOME/.cache/HEPtools/contur/python3.10 LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$HOME/.cache/HEPTools/lib ./tests/test_manager.py test_rivet_from_file -pA -t0 -l INFO
+            PYTHONPATH=$PYTHONPATH:/home/runner/.cache/HEPtools/contur/python3.10 LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/home/runner/.cache/HEPTools/lib ./tests/test_manager.py test_rivet_from_file -pA -t0 -l INFO
 
       # ---- acceptancetest_density_tttbartbar ----
       - name: "acceptancetest_density_tttbartbar"
@@ -472,18 +460,12 @@ jobs:
     # former jobs, run one after the other: acceptancetest_48
     #   acceptancetest_heft acceptancetest_madevent_flavor_zud
     # Each keeps its own steps, run even when an earlier one failed.
-    # Runs on the self-hosted alma10 runners (cern1, ...) to spare the hosted queue;
-    # fork PRs stay on ubuntu-24.04 so outside code never runs on our machines.
-    runs-on: ${{ github.event.pull_request.head.repo.fork && 'ubuntu-24.04' || fromJSON('["self-hosted", "alma10"]') }}
+    runs-on: ubuntu-24.04
     if: github.event_name == 'push' || github.event.pull_request.head.repo.fork == true
     steps:
       - uses: actions/checkout@v4
       - uses: ./.github/actions/checkout_mg5
       - uses: ./.github/actions/restore_heptools
-        # only what these tests need: rivet/contur and the loop libraries are
-        # not built on the (small) self-hosted machines
-        with:
-          selfhosted_tools: lhapdf boost pythia8 emela
 
       # ---- acceptancetest_48 ----
       - name: "acceptancetest_48"
@@ -512,9 +494,7 @@ jobs:
 
   acceptancetest_53:
     # The type of runner that the job will run on
-    # Runs on the self-hosted alma10 runners (cern1, ...) to spare the hosted queue;
-    # fork PRs stay on ubuntu-24.04 so outside code never runs on our machines.
-    runs-on: ${{ github.event.pull_request.head.repo.fork && 'ubuntu-24.04' || fromJSON('["self-hosted", "alma10"]') }}
+    runs-on: ubuntu-24.04
     if: github.event_name == 'push' || github.event.pull_request.head.repo.fork == true
 
     # Steps represent a sequence of tasks that will be executed as part of the job
@@ -523,10 +503,6 @@ jobs:
       - uses: actions/checkout@v4
       - uses: ./.github/actions/checkout_mg5
       - uses: ./.github/actions/restore_heptools
-        # only what these tests need: rivet/contur and the loop libraries are
-        # not built on the (small) self-hosted machines
-        with:
-          selfhosted_tools: lhapdf boost pythia8 emela
       - uses: ./.github/actions/restore-pip-cache
       - uses: ./.github/actions/restore_ufomodel
 
@@ -561,7 +537,7 @@ jobs:
       - name: test one of the test test_loop_improved_reweighting
         run: |
             cd $GITHUB_WORKSPACE
-            export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$HOME/.cache/HEPtools/lhapdf6_py3/lib
+            export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/home/runner/.cache/HEPtools/lhapdf6_py3/lib
             export PYTHONPATH=$PYTHONPATH:~/.cache/HEPtools/lhapdf6_py3/lib/python3.12/dist-packages
             export PYTHONPATH=$PYTHONPATH:~/.cache/HEPtools/lhapdf6_py3/lib/python3.10/dist-packages
             ./tests/test_manager.py  test_nlo_reweighting -pA -t0 -l INFO
@@ -571,7 +547,7 @@ jobs:
         if: ${{ !cancelled() }}
         run: |
             cd $GITHUB_WORKSPACE
-            export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$HOME/.cache/HEPtools/lhapdf6_py3/lib
+            export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/home/runner/.cache/HEPtools/lhapdf6_py3/lib
             export PYTHONPATH=$PYTHONPATH:~/.cache/HEPtools/lhapdf6_py3/lib/python3.12/dist-packages
             export PYTHONPATH=$PYTHONPATH:~/.cache/HEPtools/lhapdf6_py3/lib/python3.10/dist-packages
             ./tests/test_manager.py  test_nlo_reweighting_new_parameter -pA -t0 -l INFO
@@ -587,18 +563,12 @@ jobs:
     # former jobs, run one after the other: acceptancetest_103_polarization
     #   acceptancetest_flavor acceptancetest_madevent_vbf_merged_flavor
     # Each keeps its own steps, run even when an earlier one failed.
-    # Runs on the self-hosted alma10 runners (cern1, ...) to spare the hosted queue;
-    # fork PRs stay on ubuntu-24.04 so outside code never runs on our machines.
-    runs-on: ${{ github.event.pull_request.head.repo.fork && 'ubuntu-24.04' || fromJSON('["self-hosted", "alma10"]') }}
+    runs-on: ubuntu-24.04
     if: github.event_name == 'push' || github.event.pull_request.head.repo.fork == true
     steps:
       - uses: actions/checkout@v4
       - uses: ./.github/actions/checkout_mg5
       - uses: ./.github/actions/restore_heptools
-        # only what these tests need: rivet/contur and the loop libraries are
-        # not built on the (small) self-hosted machines
-        with:
-          selfhosted_tools: lhapdf boost pythia8 emela
 
       # ---- acceptancetest_103_polarization ----
       - name: "acceptancetest_103_polarization"