diff --git a/.github/actions/build-wheel/action.yml b/.github/actions/build-wheel/action.yml
index 5f5127e0..e29347c8 100644
--- a/.github/actions/build-wheel/action.yml
+++ b/.github/actions/build-wheel/action.yml
@@ -118,9 +118,11 @@ runs:
     # - cibw will change its cwd to a temp dir and create a separate venv for testing. It then installs the wheel it
     #   built into that venv, and run the CIBW_TEST_COMMAND. We have to install all dependencies ourselves, and make
     #   sure that the pytest config in pyproject.toml is available.
-    # - CIBW_BEFORE_TEST installs the test dependencies by exporting them into a pylock.toml. At the time of writing,
-    #   `uv sync --no-install-project` had problems correctly resolving dependencies using resolution environments
-    #   across all platforms we build for. This might be solved in newer uv versions.
+    # - CIBW_BEFORE_TEST installs the test dependencies with `uv sync --active --only-group test --no-install-project`
+    #   into cibw's test venv. Exporting them into a pylock.toml instead downloads every wheel of the resolution that
+    #   has no index hash (a new torch release's, for every platform) to compute one. An older uv had trouble
+    #   resolving the sync across our resolution environments (tool.uv.environments in pyproject.toml); look there if
+    #   a platform fails.
     # - CIBW_TEST_COMMAND specifies pytest conf from pyproject.toml. --confcutdir is needed to prevent pytest from
     #   traversing the full filesystem, which produces an error on Windows.
     # - CIBW_TEST_SKIP we always skip tests for *-macosx_universal2 builds, because we run tests for arm64 and x86_64.
@@ -132,8 +134,7 @@ runs:
         CIBW_TEST_SKIP: ${{ inputs.testsuite == 'none' && '*' || '*-macosx_universal2' }}
         CIBW_TEST_SOURCES: tests
         CIBW_BEFORE_TEST: >
-          uv export --only-group test --no-emit-project  --quiet --output-file pylock.toml --directory {project} &&
-          uv pip install -r pylock.toml
+          uv sync --active --inexact --only-group test --no-install-project --directory {project}
         CIBW_TEST_COMMAND: >
           uv run -v pytest --confcutdir=. --rootdir . -c {project}/pyproject.toml ${{ inputs.testsuite == 'fast' && './tests/fast' || './tests' }}
 
diff --git a/.github/workflows/packaging_sdist.yml b/.github/workflows/packaging_sdist.yml
index a76a55fa..8a70cd79 100644
--- a/.github/workflows/packaging_sdist.yml
+++ b/.github/workflows/packaging_sdist.yml
@@ -89,10 +89,11 @@ jobs:
       - name: Test sdist
         if: ${{ inputs.testsuite != 'none' }}
         run: |
-          # install the test requirements
-          uv export --only-group test --no-emit-project --output-file ${{ runner.temp }}/pylock.toml --quiet
+          # install the test requirements next to the sdist already in the venv; a sync installs only this
+          # platform's wheels, where an export to a pylock downloads every hashless wheel of the resolution (a new
+          # torch release's, for every platform) to compute its hash
+          UV_PROJECT_ENVIRONMENT="${{ runner.temp }}/.venv" uv sync --only-group test --no-install-project --inexact
           cd ${{ runner.temp }}
-          uv pip install -r pylock.toml
           # run tests
           tests_root="${{ github.workspace }}/tests"
           tests_dir="${tests_root}${{ inputs.testsuite == 'fast' && '/fast' || '/' }}"
diff --git a/.github/workflows/packaging_wheels.yml b/.github/workflows/packaging_wheels.yml
index 205b30d9..1e2275dd 100644
--- a/.github/workflows/packaging_wheels.yml
+++ b/.github/workflows/packaging_wheels.yml
@@ -243,8 +243,9 @@ jobs:
         run: |
           set -eo pipefail
           uv venv --python "${{ matrix.python }}" .venv-wheel
-          uv export --only-group test --no-emit-project --quiet --output-file pylock.toml
-          uv pip install --python .venv-wheel -r pylock.toml
+          # A sync installs only this platform's wheels; an export to a pylock downloads every wheel of the universal
+          # resolution that has no index hash to compute one, such as a new torch release's wheels for every platform.
+          UV_PROJECT_ENVIRONMENT="$PWD/.venv-wheel" uv sync --only-group test --no-install-project --python "${{ matrix.python }}"
           uv pip install --python .venv-wheel wheelhouse/*.whl
           venv="$PWD/.venv-wheel"
           testrun=$(uv run --no-project --python "$venv" python -c 'import tempfile; print(tempfile.mkdtemp(prefix="duckdb-testrun-"))')