### Check existing issues - [x] I've verified that this bug isn't described by any existing issues. ### Bug description Building a 12-factor charm (fastapi in this case), results in a larger venv than necessary. My gut feeling is that the build dependencies are left in the venv, though some other deps are also there, which are not trivial to categorise. ### Steps to reproduce ### Charm `charmcraft pack` this charm: https://github.com/canonical/roadmap.canonical.com/tree/main/charm (or `juju download canonical-roadmap --channel latest/edge`) unpack the charm `ls venv/| sort > from-charmcraft-pack` ### What's required Observe that https://github.com/canonical/roadmap.canonical.com/blob/main/charm/pyproject.toml doesn't list dependencies Only https://github.com/canonical/roadmap.canonical.com/blob/main/charm/requirements.txt does Create a new venv: `python3.12 -m venv test-paas` and activate Install the deps: `pip install -r requirements.txt` See what got installed: `ls test-paas/lib/python3.12/site-packages/| sort > from-paas-charm` ### Compare the two files: ```diff (test-paas) ⋊> dima@bb ⋊> ~/tmp-rdm diff from-paas-charm from-charmcraft-pack 08:58:17 7c7,15 < cosl-1.9.1.dist-info --- > cosl-1.6.1.dist-info > _distutils_hack > distutils-precedence.pth > dns > dnspython-2.8.0.dist-info > email_validator > email_validator-2.3.0.dist-info > idna > idna-3.11.dist-info 19c27 < opentelemetry_api-1.41.0.dist-info --- > opentelemetry_api-1.40.0.dist-info 24c32,34 < paas_charm-1.11.1.dist-info --- > paas_charm-1.11.0.dist-info > packaging > packaging-26.0.dist-info 26c36 < pip-24.0.dist-info --- > pip-24.1.1.dist-info 36a47,48 > setuptools > setuptools-82.0.1.dist-info 44a57,58 > wheel > wheel-0.46.3.dist-info 48c62 < zipp-3.23.1.dist-info --- > zipp-3.23.0.dist-info ``` There are two groups of extra deps: - `packaging, setuptools, wheel` which appear to be build dependencies - `_distutils_hack, distutils-precendence` which may also be - `dns, dns_python, email_validator, idna` I guess `pydantic`'s extra? ### Environment regular charmcraft pack ### charmcraft.yaml ```yaml name: canonical-roadmap type: charm base: ubuntu@24.04 # the platforms this charm should be built on and run on. # you can check your architecture with `dpkg --print-architecture` platforms: amd64: # arm64: # ppc64el: # s390x: summary: FastAPI web service of roadmap.canonical.com description: | Read more about the project on https://github.com/canonical/roadmap.canonical.com extensions: - fastapi-framework requires: postgresql: interface: postgresql_client optional: false limit: 1 config: options: jira-url: description: | The base URL of the Jira instance. default: "https://xxx.atlassian.net" type: string jira-username: description: | The username (email) used to authenticate with Jira. type: string jira-pat: description: | The Jira Personal Access Token used for authentication. type: string jql-filter: description: | Additional JQL filter appended to the dynamically built query. Cycle labels are derived automatically from registered cycles in the database — do NOT include "labels in (...)" here. default: "issuetype = Epic" type: string oidc-client-id: description: | The OIDC client ID for authenticating users. Leave empty to disable authentication. type: string oidc-client-secret: description: | The OIDC client secret. type: string oidc-issuer: description: | The OIDC issuer URL. Used for OpenID Connect discovery. default: "https://iam.green.canonical.com" type: string oidc-redirect-uri: description: | The full callback URL for the OIDC redirect (e.g. https://roadmap.canonical.com/callback). type: string session-secret: description: | Secret key used to sign the session cookie. Must be set to a stable random value for multi-replica deployments. type: string sync-interval-seconds: description: | Interval (in seconds) between automatic Jira syncs. Set to 0 to disable the periodic sync entirely. default: 3600 type: int ``` ### Log output ```shell N/A ```