Stage package filtering doesn't deal with foreign arch packages (e.g. i386 on amd64)
Metadata
Current evaluation
Stage package filtering in craft-parts deb.py matches by name only, ignoring architecture, so foreign-arch packages (e.g. i386 on amd64) pull in duplicate content like all of libc6. Confirmed still present on core26; maintainer says it is a design-first task needing craft-team coordination.
Suggested action: keep open
Reason: Maintainer @mr-cal (2026-07-02) explicitly acknowledged this as a valid bug requiring a design-first approach by a craft team member, and @Saviq confirmed the behaviour still reproduces on core26. The underlying code (_get_filtered_stage_package_names in craft-parts deb.py) still performs name-only matching, so the bug is unfixed. It is triaged, scoped, and awaiting architectural design, so it should remain open.
Impact:
45
Quick Win:
13.5
Staleness:
40
Complexity:
70
Confidence:
80
Support Request:
5
Issue body
### Check existing issues
- [x] I've verified that this bug isn't described by any existing issues.
### Bug description
The code filtering stage packages only matches packages by name, ignoring architecture:
https://github.com/canonical/craft-parts/blob/c5bf8edf35b0739081cd354c1c695496f5a4be2b/craft_parts/packages/deb.py#L316-L332
This results in duplicate content in downstream snaps if foreign architecture packages are included.
This was originally filed in https://bugs.launchpad.net/snapcraft/+bug/2076115, though not understood enough.
### Steps to reproduce
`snapcraft pack` the YAML below and inspect the contents, you'll see not only `liblzma5`, but also all of `libc6` in the resulting snap:
```
$ tree squashfs-root
squashfs-root
├── etc
│ └── ld.so.conf.d
│ └── i386-linux-gnu.conf
├── meta
│ ├── gui
│ └── snap.yaml
└── usr
├── bin
│ ├── lzmainfo
│ ├── unxz -> xz
│ ├── xz
│ ├── xzcat -> xz
│ ├── xzcmp -> xzdiff
│ ├── xzdiff
│ ├── xzegrep -> xzgrep
│ ├── xzfgrep -> xzgrep
│ ├── xzgrep
│ ├── xzless
│ └── xzmore
├── lib
│ ├── i386-linux-gnu
│ │ ├── gconv
│ │ │ ├── ANSI_X3.110.so
# ...
│ │ │ └── VISCII.so
│ │ ├── ld-linux.so.2
│ │ ├── libanl.so.1
│ │ ├── libBrokenLocale.so.1
│ │ ├── libc_malloc_debug.so.0
│ │ ├── libc.so.6
│ │ ├── libdl.so.2
│ │ ├── libgcc_s.so.1
│ │ ├── liblzma.so.5 -> liblzma.so.5.4.5
│ │ ├── liblzma.so.5.4.5
│ │ ├── libmemusage.so
│ │ ├── libm.so.6
│ │ ├── libnsl.so.1
│ │ ├── libnss_compat.so.2
│ │ ├── libnss_dns.so.2
│ │ ├── libnss_files.so.2
│ │ ├── libnss_hesiod.so.2
│ │ ├── libpcprofile.so
│ │ ├── libpthread.so.0
│ │ ├── libresolv.so.2
│ │ ├── librt.so.1
│ │ ├── libthread_db.so.1
│ │ └── libutil.so.1
│ └── ld-linux.so.2 -> i386-linux-gnu/ld-linux.so.2
# ...
```
Most of that is also available in the `core24` snap, and shouldn't be staged.
### Environment
Ubuntu 25.10
Snapcraft 8.13.2
### snapcraft.yaml
```yaml
name: base-cleanup
base: core24
version: '0.1'
summary: Cleanup verifier
description: Cleanup verifier
grade: devel
confinement: devmode
package-repositories:
- type: apt
url: http://archive.ubuntu.com/ubuntu
suites: [noble]
components: [main]
architectures: [i386]
key-id: F6ECB3762474EDA9D21B7022871920D1991BC93C
key-server: keyserver.ubuntu.com
parts:
my-part:
plugin: nil
stage-packages:
- xz-utils:i386
```
### Log output
```shell
```
Evaluation history
| Date | Model | Scores | Action | Summary |
|---|---|---|---|---|
| qwen/qwen3.8-27b |
Impact:
45
Quick Win:
13.5
Staleness:
40
Complexity:
70
Confidence:
80
Support Request:
5
|
keep open | Stage package filtering in craft-parts deb.py matches by name only, ignoring architecture, so foreign-arch packages (e.g. i386 on amd64) pull in duplicate content like all of libc6. Confirmed still present on core26; maintainer says it is a design-first task needing craft-team coordination. | |
| qwen/qwen3.6-35b-a3b |
Staleness:
15
Complexity:
75
Confidence:
85
Support Request:
5
|
keep open | Stage package filtering ignores architecture, causing duplicate foreign arch content in snaps. Maintainers acknowledge it as a valid bug but note it requires architectural design and backward compatibility considerations before implementation. | |
| qwen3.6-35b-a3b-mtp-q6 |
Staleness:
20
Complexity:
75
Confidence:
85
Support Request:
5
|
keep open | Stage package filtering ignores architecture, causing duplicate foreign arch packages in snaps. Maintainers have acknowledged the bug but note it requires architectural design and team coordination before implementation. | |
| qwen3.6-35b-a3b-mtp-q6 |
Staleness:
45
Complexity:
40
Confidence:
85
Support Request:
5
|
needs triage | Stage package filtering ignores architecture, causing duplicate foreign arch packages in snaps. Impacts content snaps and desktop extensions. Open with two comments exploring dpkg-based deduplication. Requires triage and code fix. |
Update history
No update history recorded yet.
Related work
-
Related To:
snapcraft#5998
(confidence 75%)
Both issues stem from architecture information being dropped in craft-parts deb.py; #5998 is about manifest.yaml losing arch qualifiers (fixed by craft-parts PR #1558), while #5997 is about the stage-package filter ignoring arch.
Related issues
| Issue | Project | State | Summary | Similarity |
|---|---|---|---|---|
| #2012503 wrong arch of stage packages | snapcraft (launchpad) | open | Snapcraft 7.3 picks host architecture for stage packages when cross-building (build-on amd64, build-for arm64). No maintainer response in 3.4 years. Nearly identical issue #5335 was closed as expected behavior requiring explicit :$CRAFT_ARCH_BUILD_FOR suffix on stage packages. |