core26: apt update fails due to armhf being added to the architectures list on arm64 platforms
Metadata
Current evaluation
core26 snap builds on arm64 fail because craft-archives adds armhf to architectures list, causing apt update to fail with 404 errors from archive.ubuntu.com
Suggested action: keep open
Reason: The issue is triaged (Status: Triaged label present), has active maintainer engagement (@mr-cal responded on 2026-07-08 with an upstream issue reference and workaround), and blocks core26 snap builds on arm64 platforms. The upstream fix is tracked in craft-archives#230.
Impact:
75
Quick Win:
45.0
Staleness:
45
Complexity:
40
Confidence:
85
Support Request:
15
Issue body
### Check existing issues
- [x] I've verified that this bug isn't described by any existing issues.
### Bug description
Building a core26 snap on an arm64 host running 26.04 can result in the behaviour shown in the logs when snapcraft tries to update the apt sources list.
This is due to `armhf` automatically being added as an architecture as per https://github.com/canonical/craft-archives/blob/1b6bf121b3756ef420e0e9991c1a69da278d8490/craft_archives/repo/apt_sources_manager.py#L46 and the recent move of the arm64 archives to archive.ubuntu.com (armhf packages were not added). Previously, both arm64 and armhf packages were available in one place on ports.ubuntu.com, but recent arm64 LXD images use the new URL.
### Steps to reproduce
Build a core26 arm64 snap in a clean LXD environment with a recent image.
### Environment
Running on an arm64 self-hosted GitHub runner using the `snapcore/action-build` action, which uses LXD to run the build.
### snapcraft.yaml
```yaml
```
### Log output
```shell
:: 2026-07-07 09:22:09.425 Reading sources from '/etc/apt/sources.list.d/ubuntu.sources'.
:: 2026-07-07 09:22:09.425 Updating field 'Architectures' to 'arm64 armhf'
:: 2026-07-07 09:22:09.425 Updating source 'http://archive.ubuntu.com/ubuntu/'.
:: 2026-07-07 09:22:09.425 Updating source 'http://security.ubuntu.com/ubuntu/'.
:: 2026-07-07 09:22:09.425 Writing updated sources to '/etc/apt/sources.list.d/ubuntu.sources'.
:: 2026-07-07 09:22:09.425 Writing updated sources to '/etc/apt/sources.list.d/ubuntu.sources'.
:: 2026-07-07 09:22:09.425 Adding repository architecture: arm64
:: 2026-07-07 09:22:09.431 Refreshing repositories
...
:: 2026-07-07 09:22:20.233 :: Reading package lists...
:: 2026-07-07 09:22:20.251 :: E: Failed to fetch http://security.ubuntu.com/ubuntu/dists/resolute-security/main/binary-armhf/Packages 404 Not Found [IP: 91.189.91.95 80]
:: 2026-07-07 09:22:20.251 :: E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/resolute/main/binary-armhf/Packages 404 Not Found [IP: 185.125.190.94 80]
:: 2026-07-07 09:22:20.251 :: E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/resolute-updates/main/binary-armhf/Packages 404 Not Found [IP: 185.125.190.94 80]
```
Evaluation history
| Date | Model | Scores | Action | Summary |
|---|---|---|---|---|
| qwen3.6-35b-a3b-mtp-q6 |
Impact:
75
Quick Win:
45.0
Staleness:
45
Complexity:
40
Confidence:
85
Support Request:
15
|
keep open | core26 snap builds on arm64 fail because craft-archives adds armhf to architectures list, causing apt update to fail with 404 errors from archive.ubuntu.com | |
| qwen/qwen3.6-35b-a3b |
Staleness:
15
Complexity:
45
Confidence:
90
Support Request:
10
|
keep open | Bug where apt update fails on arm64 core26 snaps because armhf is incorrectly added to architectures, causing 404s. Triaged, upstream fix in craft-archives, workaround available, awaiting implementation. | |
| qwen3.6-35b-a3b-mtp-q6 |
Staleness:
5
Complexity:
45
Confidence:
85
Support Request:
10
|
needs triage | Bug in craft-archives where armhf is incorrectly added to apt architectures on arm64 platforms, causing apt update failures with 404 errors when building core26 snaps. Currently untriaged with no maintainer response. |
Update history
No update history recorded yet.
Related work
-
Blocked By:
canonical/craft-archives#230
(confidence 95%)
@mr-cal explicitly created this upstream issue in craft-archives to track the fix for the armhf architecture detection logic in apt_sources_manager.py
Related issues
No related issues found above the similarity threshold.