bash gets built with a /bin/bash that is missing the executable bit
Metadata
Current evaluation
Staging bash+quilt in a classic snap yields a non-executable bin/bash because craft-parts normalize copies the symlink target from the system via shutil.copyfile, dropping the executable bit. Unfixed in craft-parts; reporter has a chmod workaround.
Suggested action: keep open
Reason: A maintainer (lengau) triaged it, pinpointed the exact code (craft_parts/packages/normalize.py _try_copy_local, lines 148-157) and confirmed the root cause: shutil.copyfile copies content but not the file mode, so the executable bit is lost. The current craft-parts HEAD still uses shutil.copyfile at that line, so the bug is unfixed. It is a real, reproducible bug with a clear minimal reproducer, not a support request, so it should stay open.
Impact:
45
Quick Win:
31.5
Staleness:
70
Complexity:
30
Confidence:
70
Support Request:
10
Issue body
### Bug Description
If I stage the `bash` and `quilt` packages in a part in a classic snap, then the snap gets built with a `bin/bash` file that is not executable. Subsequent attempts to use it fail.
### To Reproduce
On a fresh Noble VM:
```
sudo snap install --classic snapcraft
# installs 8.4.3 (12823)
mkdir -p demo/snap
cat > demo/snap/snapcraft.yaml <<EOT
name: demo
version: 1
summary: demo
description: demo
confinement: classic
grade: devel
base: core24
apps:
demo:
command: usr/bin/bash
parts:
demo:
build-attributes: [enable-patchelf]
plugin: nil
stage-packages: [bash, quilt]
EOT
cd demo
snapcraft build --destructive-mode
```
Expected result: `parts/demo/install/bin/bash` is executable, and this passes through to the final snap (if you continue you should also see it in `prime/bin/bash` as executable, etc).
Actual result: `parts/demo/install/bin/bash` is not executable and this passes through to the final snap. Then scripts that try to use it fail.
### Environment
Ubuntu 24.04 cloud image, snapcraft in destructive mode. Snapcraft snap 8.4.3 (12823).
### snapcraft.yaml
```yaml
name: demo
version: 1
summary: demo
description: demo
confinement: classic
grade: devel
base: core24
apps:
demo:
command: usr/bin/bash
parts:
demo:
build-attributes: [enable-patchelf]
plugin: nil
stage-packages: [bash, quilt]
```
### Relevant log output
```shell
2024-10-13 13:12:26.879 Building demo
2024-10-13 13:12:26.893 execute action demo:Action(part_name='demo', step=Step.BUILD, action_type=ActionType.RUN, reason=None, project_vars=None, properties=ActionProperties(changed_files=None, changed_dirs=None))
2024-10-13 13:12:26.894 load state file: /home/ubuntu/demo/parts/demo/state/pull
2024-10-13 13:12:28.158 fix artifacts: unpack_dir='/home/ubuntu/demo/parts/demo/install'
2024-10-13 13:12:28.175 fix symlink: path='/home/ubuntu/demo/parts/demo/install/usr/share/quilt/compat/bash', unpack_dir='/home/ubuntu/demo/parts/demo/install', root='/home/ubuntu/demo/parts/demo/install/usr/share/quilt/compat'
2024-10-13 13:12:28.207 fix symlink: target='/home/ubuntu/demo/parts/demo/install/bin/bash'
2024-10-13 13:12:28.207 Copying needed target link from the system: /usr/bin/bash
2024-10-13 13:12:30.039 remove directory /home/ubuntu/demo/parts/demo/build
2024-10-13 13:12:30.041 Executing PosixPath('/home/ubuntu/demo/parts/demo/run/build.sh')
```
### Additional context
The trace output suggests that snapcraft is doing something because `usr/share/quilt/compat/bash` is a symlink. If I drop `quilt` from `stage-packages`, then `bin/bash` isn't created.
I found this when trying to move the git-ubuntu snap to core24. That's complex enough so I came up with a minimal reproducer.
Workaround: I did this:
```
override-stage: |
craftctl default
chmod 755 bin/bash
```
Evaluation history
| Date | Model | Scores | Action | Summary |
|---|---|---|---|---|
| qwen/qwen3.8-27b |
Impact:
45
Quick Win:
31.5
Staleness:
70
Complexity:
30
Confidence:
70
Support Request:
10
|
keep open | Staging bash+quilt in a classic snap yields a non-executable bin/bash because craft-parts normalize copies the symlink target from the system via shutil.copyfile, dropping the executable bit. Unfixed in craft-parts; reporter has a chmod workaround. | |
| qwen/qwen3.6-35b-a3b |
Staleness:
88
Complexity:
55
Confidence:
75
Support Request:
10
|
close stale | Staging bash and quilt in a classic snap causes /bin/bash to lose its executable bit due to craft-parts symlink normalization. The issue has been inactive for over a year with a provided workaround but no fix. | |
| qwen3.6-35b-a3b-mtp-q6 |
Staleness:
95
Complexity:
45
Confidence:
85
Support Request:
15
|
close stale | Staging bash and quilt in a classic snap causes bin/bash to lose its executable bit. Currently inactive for over 630 days with a workaround available. | |
| qwen3.6-35b-a3b-mtp-q6 |
Staleness:
88
Complexity:
45
Confidence:
60
Support Request:
10
|
close stale | Staging bash in classic snaps strips the executable bit from bin/bash, breaking execution. Discussion centers on whether craft-parts should preserve permissions and rewrite absolute symlinks for quilt. Issue remains open and awaiting triage. |
Update history
No update history recorded yet.
Related work
-
Caused By:
craft-parts#148
(confidence 40%)
Root cause is in craft-parts normalize.py _try_copy_local (shutil.copyfile drops the mode bit); the issue links to that file/lines but no specific craft-parts issue number is cited, so the ref is approximate.
Related issues
No related issues found above the similarity threshold.