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SNAPCRAFT_MAX_PARALLEL_BUILD_COUNT doesn't seem to be passed through to lxd container

View original Launchpad issue

Metadata

Project
snapcraft (launchpad)
Number
#1997874
Type
issue
State
closed
Author
~ilya-fedin
Labels
—
Created
Updated
Closed

Current evaluation

SNAPCRAFT_MAX_PARALLEL_BUILD_COUNT was not forwarded into the LXD/Multipass build instance. Fixed by merged PR snapcore/snapcraft#3997 (commit 31a3990c8, 'providers: pass SNAPCRAFT_MAX_PARALLEL_BUILD_COUNT to instance'), released in snapcraft 7.3.

Resolution: closed resolved

Reason: Maintainer reproduced the failure and landed the one-line fix in PR snapcore/snapcraft#3997, commit 31a3990c8, which passes the env var into the LXD/Multipass instance. A follow-up commit 1f8bef63c (#4041) added logging when the value is invalid, and the maintainer closed the issue noting it shipped in snapcraft 7.3.

Evaluated by: mr-cal-bot

No scores available.

Issue body

I'm affected by https://github.com/lxc/lxd/issues/10034 and was asked to decrease the amount of jobs used in the build command. I tried to set SNAPCRAFT_MAX_PARALLEL_BUILD_COUNT, but nothing changed, it still uses the CPU count.

Evaluation history

Date Model Scores Action Summary
stealth/space-bunny-alpha — closed resolved SNAPCRAFT_MAX_PARALLEL_BUILD_COUNT was not forwarded into the LXD/Multipass build instance. Fixed by merged PR snapcore/snapcraft#3997 (commit 31a3990c8, 'providers: pass SNAPCRAFT_MAX_PARALLEL_BUILD_COUNT to instance'), released in snapcraft 7.3.
qwen/qwen3.8-27b — closed resolved Fixed: snapcraft wasn't forwarding SNAPCRAFT_MAX_PARALLEL_BUILD_COUNT into the LXD/Multipass build instance. Resolved by PR #3997 (commit 31a3990c8) and shipped in snapcraft 7.3.
stealth/space-bunny-alpha — closed resolved Env var wasn't forwarded into LXD/Multipass build instances. Reproduced by maintainer and fixed by PR #3997 (commit 31a3990c8), adding it to the pass-through env in snapcraft/providers.py; released in snapcraft 7.3.
stealth/space-bunny-alpha — closed resolved SNAPCRAFT_MAX_PARALLEL_BUILD_COUNT was not forwarded into the LXD/Multipass build instance. Fixed by merged PR #3997 (commit 31a3990c8) adding it to the provider env pass-through; shipped in snapcraft 7.3.
stealth/space-bunny-alpha — closed stale Closed as stale without comments or a recorded resolution. Snapcraft PR #3997 (31a3990c8) later fixed forwarding of SNAPCRAFT_MAX_PARALLEL_BUILD_COUNT into build instances.
qwen/qwen3.6-35b-a3b — — Closed without resolution or comments. The environment variable SNAPCRAFT_MAX_PARALLEL_BUILD_COUNT failing to pass to LXD containers remains unfixed, likely due to inactivity.
qwen/qwen3.6-35b-a3b — — SNAPCRAFT_MAX_PARALLEL_BUILD_COUNT not being passed to LXD containers was closed and abandoned. No comments, resolution, or fix were provided.
qwen/qwen3.6-35b-a3b — — SNAPCRAFT_MAX_PARALLEL_BUILD_COUNT being ignored in LXD containers was closed without comments or resolution, indicating the report was abandoned. No fix or workaround was provided.
qwen3.6-35b-a3b-mtp-q6 — — SNAPCRAFT_MAX_PARALLEL_BUILD_COUNT not passing to LXD containers was closed without comments or resolution, indicating abandonment. No fixes were applied, likely superseded by upstream LXD updates.

Update history

Date Change
created

Related work

  • Likely Fixed By: canonical/snapcraft#3997 (confidence 98%)

    Merged PR titled 'providers: pass SNAPCRAFT_MAX_PARALLEL_BUILD_COUNT to instance', commit 31a3990c8, cited by the closing maintainer comment.

  • Related To: canonical/snapcraft#4041 (confidence 75%)

    Follow-up commit 1f8bef63c logging SNAPCRAFT_MAX_PARALLEL_BUILD_COUNT when its value is invalid.

  • Caused By: lxd#10034 (confidence 70%)

    Upstream LXD build issue that prompted the reporter to limit parallel build jobs.

Related issues

Issue Project State Summary Similarity
#212 Incorrectly handling SNAPCRAFT_MAX_PARALLEL_BUILD_COUNT craft-providers open SNAPCRAFT_MAX_PARALLEL_BUILD_COUNT not honored and Multipass instances hardcoded to 2 CPUs. Maintainer triaged; still unfixed in craft-providers (cpus=2 at multipass_provider.py:300), provider-side work split out to #531, snapcraft-side partly fixed in 8.4.4.
79%
#4927 Parallel installation of snapcraft not passed to LXD instance snapcraft closed Parallel-installed (signed) snapcraft was not passed to the LXD build instance. Fixed by merged PR #5085 and backported via #5087 to hotfix/7.5, shipped in 7.5.7; also tracks upstream craft-application#411.
79%
#3997 providers: pass SNAPCRAFT_MAX_PARALLEL_BUILD_COUNT to instance snapcraft merged PR #3997 merged (commit 31a3990c8) forwarding SNAPCRAFT_MAX_PARALLEL_BUILD_COUNT into the build provider instance, so parallel build limits are honored inside the build environment.
78%
#1988748 SNAPCRAFT_PARALLEL_BUILD_COUNT not respected if set in `override-build:` snapcraft (launchpad) closed Closed as working as intended: maintainer sergiusens explained craftctl reads the configured parallel-build count, so exporting SNAPCRAFT_PARALLEL_BUILD_COUNT inside override-build cannot change it (it is set by snapcraft itself, per PR #1154).
77%
#1985409 snapcraft-managed lxd containers do not respect parallel installs snapcraft (launchpad) closed Reported 2022 that parallel-installed snapcraft instances (e.g. snapcraft_7) launch the unsuffixed host snapcraft inside their managed LXD build container, causing '--build-for' build failures. Closed in 2026 after PR #5085 and 7.5 backport #5087.
74%
#4041 utils: log envvar SNAPCRAFT_MAX_PARALLEL_BUILD_COUNT when invalid snapcraft merged Merged PR #4041 (commit 1f8bef63c): snapcraft/utils.py get_parallel_build_count() now emits a debug log with the invalid SNAPCRAFT_MAX_PARALLEL_BUILD_COUNT value. No functional change.
73%