Snapcraft 9: cannot create directory '/snap/command-chain': Permission denied Edit

[nteodosio]

Check existing issues

• I've verified that this bug isn't described by any existing issues.

Bug description

Describe the bug, including any relevant context or screenshotFirefox builds on Docker in destructive mode fail under snapcraft 9.0.0:

[task 2026-06-16T10:09:13.478+00:00] Building gnome/gpu/wrapper
[task 2026-06-16T10:09:13.486+00:00] :: + make -j60 GPU_INTERFACE=gpu-2404
[task 2026-06-16T10:09:13.487+00:00] :: install -D -m755 gpu-wrapper "/snap/command-chain"/"gpu-2404-wrapper"
[task 2026-06-16T10:09:13.489+00:00] :: install: cannot create directory '/snap/command-chain': Permission denied
[task 2026-06-16T10:09:13.489+00:00] :: make: *** [Makefile:9: gpu-2404-wrapper] Error 1
[task 2026-06-16T10:09:13.491+00:00] Failed to run the build script for part 'gnome/gpu/wrapper'.
[task 2026-06-16T10:09:13.491+00:00] Detailed information:
[task 2026-06-16T10:09:13.491+00:00] :: + make -j60 GPU_INTERFACE=gpu-2404
[task 2026-06-16T10:09:13.491+00:00] :: install: cannot create directory '/snap/command-chain': Permission denied
[task 2026-06-16T10:09:13.491+00:00] :: make: *** [Makefile:9: gpu-2404-wrapper] Error 1

Reverting to 8.x fixes the issue.

Originally reported in https://launchpad.net/bugs/2160018.

Steps to reproduce

@mr-cal confirmed the bug so a reproducer is already available.

Environment

Snapcraft in destructive mode in Docker: https://searchfox.org/firefox-main/source/taskcluster/docker/snap-coreXX-build/Dockerfile.

snapcraft.yaml

If the issue is specific to a project, share its `snapcraft.yaml`. This field automatically renders as YAML, so you don't need to add special formatting.

Log output

https://treeherder.mozilla.org/logviewer?job_id=573086536&repo=autoland&task=DGg8cWn2SCSwSE15vfULlQ.0&lineNumber=107498

[mr-cal]

Thanks for reporting @nteodosio, I can confirm this is a bug.

I reproduced this with the following snapcraft.yaml:

name: lp-2160018
version: "1.0"
summary: Reproducer for LP bug #2160018
description: |
  Minimal reproducer for lp#2160018.

grade: devel
base: core24
confinement: strict

apps:
  app:
    command: usr/bin/true
    extensions: [gnome]

parts:
  app:
    plugin: nil
    override-build: |
      install -d "$CRAFT_PART_INSTALL/usr/bin"
      install -m 755 /usr/bin/true "$CRAFT_PART_INSTALL/usr/bin/true"

Packing this snap shows that it's creating /snap/command-chain/gpu-2404-wrapper:

> snapcraft pack --verbosity=trace # verbose to get the name of the container

> lxc --project snapcraft start snapcraft-lp-2160018-amd64-38176125

> lxc --project snapcraft exec snapcraft-lp-2160018-amd64-38176125 -- ls -lR /snap/command-chain
/snap/command-chain:
total 1
-rwxr-xr-x 1 root root 666 Jul  7 07:27 gpu-2404-wrapper

I think the problem is here:

snapcraft/extensions/gpu/command-chain/Makefile

Line 3 in 429f628

BIN_DIR := $(DESTDIR)/snap/command-chain

When DESTDIR is undefined in the gpu extension's Makefile, it creates /snap/command-chain/gpu-2404-wrapper in the wrong location. This silently no-ops in lxd and multipass containers, where snapcraft runs with root permissions. But it fails in destructive mode or in docker, where there are insufficient permissions to create /snap/command-chain/.

[syncronize-issues-to-jira]

Thank you for reporting your feedback to us!

The internal ticket has been created: https://warthogs.atlassian.net/browse/SNAPCRAFT-1366.

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