`charmcraft pack` Internal error on a 26.04 host

[panlinux]

Check existing issues

• 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.

[st3v3nmw]

Using the version from the latest edge seems to fix this, at least for now.