[raulcd]

TBD

Rationale for this change

Several Linux Packaging jobs are currently failing with out of space on the verify reproducibility step. This is due to /tmp size. Ubuntu runner image changed from Ubuntu 24.04 to Ubuntu 26.04 where the /tmp folder is mounted.
In the past the /tmp folder was on the root disk which had 145 GB of disk space.

 Filesystem      Size  Used Avail Use% Mounted on
/dev/root       145G   60G   85G  42% /
tmpfs           7.9G   84K  7.9G   1% /dev/shm
tmpfs           3.2G  988K  3.2G   1% /run
tmpfs           5.0M     0  5.0M   0% /run/lock
efivarfs        128M   32K  128M   1% /sys/firmware/efi/efivars
/dev/sda16      881M   85M  735M  11% /boot
/dev/sda15      105M  6.2M   99M   6% /boot/efi
tmpfs           1.6G   12K  1.6G   1% /run/user/1001

With the new runner the /tmp folder is on tmpfs with 7.8GB.

2026-10-23T02:23:08.8104328Z Filesystem      Size  Used Avail Use% Mounted on
2026-10-23T02:23:08.8104761Z /dev/root       145G   58G   88G  40% /
2026-10-23T02:23:08.8105145Z tmpfs           7.9G     0  7.9G   0% /dev/shm
2026-10-23T02:23:08.8105751Z tmpfs           3.2G 1000K  3.2G   1% /run
2026-10-23T02:23:08.8106428Z efivarfs        128M   32K  128M   1% /sys/firmware/efi/efivars
2026-10-23T02:23:08.8107172Z tmpfs           7.9G   38M  7.8G   1% /tmp
2026-10-23T02:23:08.8108065Z none            1.0M     0  1.0M   0% /run/credentials/systemd-journald.service
2026-10-23T02:23:08.8109058Z none            1.0M     0  1.0M   0% /run/credentials/systemd-resolved.service
2026-10-23T02:23:08.8109866Z /dev/sda13      989M   81M  842M   9% /boot
2026-10-23T02:23:08.8110512Z /dev/sda15      105M  6.3M   99M   7% /boot/efi
2026-10-23T02:23:08.8111184Z none            1.0M     0  1.0M   0% /run/credentials/systemd-networkd.service
2026-10-23T02:23:08.8112063Z tmpfs           1.6G  8.0K  1.6G   1% /run/user/1001
2026-10-23T02:23:08.8112526Z none            1.0M     0  1.0M   0% /run/credentials/getty@tty1.service
2026-10-23T02:23:08.8113053Z none            1.0M     0  1.0M   0% /run/credentials/serial-getty@ttyS0.service

What changes are included in this PR?

Use runner.temp (RUNNER_TEMP) to get a temporary directory on the runner instead of using /tmp.
See https://docs.github.com/en/actions/reference/workflows-and-actions/contexts and https://docs.github.com/en/actions/reference/workflows-and-actions/variables

Are these changes tested?

Yes via CI

Are there any user-facing changes?

No

Was AI used for this PR?

In accordance to the AI generation guidelines, please disclose below whether and how AI was used in this PR.

PR code and description written by:

• Human
• AI

Reviewed before submission by:

• Human
• AI
• Not reviewed

• GitHub Issue: [CI][Packaging] Reproducible builds on Debian fail due to out of space #54928

[github-actions]

⚠️ GitHub issue #54928 has been automatically assigned in GitHub to PR creator.

[Copilot]

🟢 Approval recommended

The narrow environment change addresses the reported storage limit without changing build commands or other workflow steps.

No open issues 🎉

What changed in this PR

Addresses GH-54928 by moving Linux package reproducibility checks’ temporary files away from size-limited /tmp storage.

Changes:

• Sets TMPDIR to ${{ runner.temp }} for the APT reproducibility step.
• Documents why reprotest needs an alternative temporary directory.

File	Description
.github/​workflows/​package_linux.yml	Redirects reproducibility-check temporary files to runner-managed storage.

_{Review effort: Balanced}

[Copilot]

🟢 Approval recommended

The narrowly scoped environment override addresses the reported storage limit without changing build commands or unrelated steps.

No open issues 🎉

_{Review effort: Balanced}

[raulcd]

@kou this should be a quick review :)

[kou]

+1

I didn't know runner.temp!