`charmcraft pack` Internal error on a 26.04 host

Metadata

Project: charmcraft
Number: #2686
Type: issue
State: closed
Author: panlinux
Labels: —
Created: 2026-05-07 07:16 PM UTC
Updated: 2026-05-21 12:28 PM UTC
Closed: 2026-09-18 03:36 PM UTC

Current evaluation

Fixed in the latest edge build; commit eeca3f79 (PR #2764) updated craft-providers to >=3.7.1 for newer Ubuntu base support.

Resolution: closed resolved

Reason: Maintainer @st3v3nmw confirmed that the latest edge build fixed the 26.04 host crash. Commit eeca3f79 in PR #2764 subsequently updated craft-providers to >=3.7.1 for support on current Ubuntu releases.

Evaluated by: mr-cal-bot

No scores available.

Issue body

### Check existing issues - [x] I've verified that this bug isn't described by any existing issues. ### Bug description When I run `charmcraft pack` on my 26.04 host, for an ubuntu@24.04 base charm, I get an internal error: ``` $ charmcraft pack charmcraft internal error: ValueError("'26.04' is not a valid BuilddBaseAlias") Full execution log: '/home/andreas/.local/state/charmcraft/log/charmcraft-20260507-160644.046754.log' ``` The log has this backtrace: ``` 2026-05-07 16:08:52.553 Executing on host: lxc query 'local:/1.0?public' 2026-05-07 16:08:52.778 charmcraft internal error: ValueError("'26.04' is not a valid BuilddBaseAlias") 2026-05-07 16:08:52.799 Traceback (most recent call last): 2026-05-07 16:08:52.800 File "/snap/charmcraft/7517/lib/python3.12/site-packages/craft_application/application.py", line 663, in run 2026-05-07 16:08:52.800 return_code = self._run_inner() 2026-05-07 16:08:52.800 ^^^^^^^^^^^^^^^^^ 2026-05-07 16:08:52.800 File "/snap/charmcraft/7517/lib/python3.12/site-packages/charmcraft/application/main.py", line 143, in _run_inner 2026-05-07 16:08:52.800 return super()._run_inner() 2026-05-07 16:08:52.800 ^^^^^^^^^^^^^^^^^^^^ 2026-05-07 16:08:52.800 File "/snap/charmcraft/7517/lib/python3.12/site-packages/craft_application/application.py", line 640, in _run_inner 2026-05-07 16:08:52.800 return_code = dispatcher.run() or os.EX_OK 2026-05-07 16:08:52.800 ^^^^^^^^^^^^^^^^ 2026-05-07 16:08:52.800 File "/snap/charmcraft/7517/lib/python3.12/site-packages/craft_cli/dispatcher.py", line 564, in run 2026-05-07 16:08:52.800 return self._loaded_command.run(self._parsed_command_args) 2026-05-07 16:08:52.800 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 2026-05-07 16:08:52.800 File "/snap/charmcraft/7517/lib/python3.12/site-packages/craft_application/commands/base.py", line 200, in run 2026-05-07 16:08:52.800 result = self._run(parsed_args, **kwargs) or result 2026-05-07 16:08:52.800 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 2026-05-07 16:08:52.800 File "/snap/charmcraft/7517/lib/python3.12/site-packages/charmcraft/application/commands/lifecycle.py", line 167, in _run 2026-05-07 16:08:52.800 result = super()._run(parsed_args, step_name, **kwargs) 2026-05-07 16:08:52.800 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 2026-05-07 16:08:52.800 File "/snap/charmcraft/7517/lib/python3.12/site-packages/craft_application/commands/lifecycle.py", line 619, in _run 2026-05-07 16:08:52.800 return super()._run(parsed_args=parsed_args, step_name=step_name) 2026-05-07 16:08:52.800 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 2026-05-07 16:08:52.800 File "/snap/charmcraft/7517/lib/python3.12/site-packages/craft_application/commands/lifecycle.py", line 232, in _run 2026-05-07 16:08:52.800 self._run_manager_for_build_plan(fetch_service_policy) 2026-05-07 16:08:52.800 File "/snap/charmcraft/7517/lib/python3.12/site-packages/craft_application/commands/lifecycle.py", line 97, in _run_manager_for_build_plan 2026-05-07 16:08:52.800 provider.run_managed(build, bool(fetch_service_policy)) 2026-05-07 16:08:52.800 File "/snap/charmcraft/7517/lib/python3.12/site-packages/craft_application/services/provider.py", line 459, in run_managed 2026-05-07 16:08:52.800 with self.instance( 2026-05-07 16:08:52.800 File "/snap/charmcraft/current/usr/lib/python3.12/contextlib.py", line 137, in __enter__ 2026-05-07 16:08:52.800 return next(self.gen) 2026-05-07 16:08:52.800 ^^^^^^^^^^^^^^ 2026-05-07 16:08:52.800 File "/snap/charmcraft/7517/lib/python3.12/site-packages/charmcraft/services/provider.py", line 117, in instance 2026-05-07 16:08:52.800 with super().instance( 2026-05-07 16:08:52.800 File "/snap/charmcraft/current/usr/lib/python3.12/contextlib.py", line 137, in __enter__ 2026-05-07 16:08:52.800 return next(self.gen) 2026-05-07 16:08:52.800 ^^^^^^^^^^^^^^ 2026-05-07 16:08:52.800 File "/snap/charmcraft/7517/lib/python3.12/site-packages/craft_application/services/provider.py", line 185, in instance 2026-05-07 16:08:52.800 with provider.launched_environment( 2026-05-07 16:08:52.800 File "/snap/charmcraft/current/usr/lib/python3.12/contextlib.py", line 137, in __enter__ 2026-05-07 16:08:52.800 return next(self.gen) 2026-05-07 16:08:52.800 ^^^^^^^^^^^^^^ 2026-05-07 16:08:52.800 File "/snap/charmcraft/7517/lib/python3.12/site-packages/craft_providers/lxd/lxd_provider.py", line 182, in launched_environment 2026-05-07 16:08:52.800 bases.ensure_guest_compatible( 2026-05-07 16:08:52.800 File "/snap/charmcraft/7517/lib/python3.12/site-packages/craft_providers/bases/checks.py", line 93, in ensure_guest_compatible 2026-05-07 16:08:52.800 host_base_alias = BuilddBaseAlias(host_os_release.get("VERSION_ID")) 2026-05-07 16:08:52.800 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 2026-05-07 16:08:52.800 File "/snap/charmcraft/current/usr/lib/python3.12/enum.py", line 757, in __call__ 2026-05-07 16:08:52.800 return cls.__new__(cls, value) 2026-05-07 16:08:52.800 ^^^^^^^^^^^^^^^^^^^^^^^ 2026-05-07 16:08:52.800 File "/snap/charmcraft/current/usr/lib/python3.12/enum.py", line 1171, in __new__ 2026-05-07 16:08:52.800 raise ve_exc 2026-05-07 16:08:52.800 ValueError: '26.04' is not a valid BuilddBaseAlias ``` ### Steps to reproduce On an ubuntu 26.04 host, run `charmcraft pack` on a charm. ### Environment Ubuntu 26.04 default LXD ### charmcraft.yaml I don't believe there are specifics in the charmcraft.yaml file. ### Log output Pasted above in the description.

Evaluation history

Date	Model	Scores	Action	Summary
2026-10-02 08:49 PM UTC	stealth/space-bunny-alpha	—	closed resolved	Fixed in the latest edge build; commit eeca3f79 (PR #2764) updated craft-providers to >=3.7.1 for newer Ubuntu base support.
2026-09-25 10:23 AM UTC	stealth/space-bunny-alpha	—	closed resolved	The Ubuntu 26.04 host crash was reported fixed in the latest edge build, but no linked PR or commit documents the change.
2026-09-17 05:23 PM UTC	qwen/qwen3.6-35b-a3b	Impact: 70 Quick Win: 50 Complexity: 20 Confidence: 85 Actionability: 90	close resolved	charmcraft pack fails on Ubuntu 26.04 host due to missing BuilddBaseAlias. Fix merged in craft-providers; user confirmed edge version resolves it.
2026-09-01 12:02 AM UTC	qwen/qwen3.8-27b	Impact: 65 Quick Win: 46 Staleness: 35 Complexity: 30 Confidence: 80 Support Request: 5	keep open	charmcraft pack crashes on Ubuntu 26.04 hosts with ValueError '26.04' is not a valid BuilddBaseAlias, raised in craft-providers' guest-compatibility check. Maintainer confirmed latest edge fixes it; main now pins craft-providers >=3.7.1 which includes the fix.
2026-09-01 12:01 AM UTC	qwen/qwen3.8-27b	Impact: 55 Quick Win: 38 Staleness: 55 Complexity: 30 Confidence: 70 Support Request: 10	keep open	charmcraft pack crashes with ValueError('26.04' is not a valid BuilddBaseAlias) on an Ubuntu 26.04 host. Root cause is in craft-providers' ensure_guest_compatible, which maps the host VERSION_ID to a BuilddBaseAlias enum that lacked 26.04. Fixed upstream in craft-providers (ignore unknown Ubuntu versions in bases check), and the latest edge reportedly works.
2026-09-01 12:01 AM UTC	qwen/qwen3.8-27b	Impact: 60 Quick Win: 45 Staleness: 45 Complexity: 25 Confidence: 70 Support Request: 10	keep open	charmcraft pack crashes on Ubuntu 26.04 hosts with ValueError: '26.04' is not a valid BuilddBaseAlias in craft-providers' ensure_guest_compatible. Fixed upstream in craft-providers (RESOLUTE alias added); reporter confirmed latest edge works. Awaiting stable release.
2026-07-21 03:26 PM UTC	qwen3.6-35b-a3b-mtp-q6	Staleness: 60 Complexity: 20 Confidence: 85 Support Request: 0	needs triage	charmcraft pack crashes on Ubuntu 26.04 hosts because 26.04 is missing from the BuilddBaseAlias enum. A commenter reports the edge version resolves it, but the issue remains unlabelled and unacknowledged by maintainers.
2026-07-07 05:41 PM UTC	qwen3.6-35b-a3b-mtp-q6	Staleness: 45 Complexity: 20 Confidence: 90 Support Request: 0	needs triage	charmcraft pack crashes on Ubuntu 26.04 hosts due to an unrecognized BuilddBaseAlias enum value. A commenter reports that the latest edge version resolves the issue, but it remains unlabelled and untriaged.

Update history

Date	Change
2026-09-18 03:36 PM UTC	closed

Related work

Likely Fixed By: canonical/charmcraft#2764 (confidence 82%)
Merged commit eeca3f79 updated craft-providers for Ubuntu 25.10/26.04-era compatibility.

Related issues

Issue	Project	State	Summary	Similarity
#2158 "Invalid hostname" error when packing charm that runs on multiple bases	charmcraft	closed	The invalid-hostname failure was fixed by canonical/craft-providers#722 (commit cabdba5), removing underscores from generated hostnames. The fix shipped through Charmcraft; Microceph's network error was Docker-related.	71%
#2631 Multiple `charmcraft pack` fail on mismatching platforms	charmcraft	open	Consecutive charmcraft pack runs with different platform sets fail: second charm (24.04 only) launches a 22.04 instance and errors 'Platform not found'. Regression from 4.0.1, still present in 4.3.1, no maintainer response.	71%