'earliest_version' doesn't work with version from a stable branch

[Stephen Finucane]

Take the following git repo:

    * ad13f52 (HEAD -> master) Fix a bug on master
    * 81b6b41 doc: Handle multiple branches in release notes
    | * 9723350 (tag: 1.0.1, stable/1.0) Fix a bug on stable
    | * 49e2158 (tag: 1.0.0) Release 1.0
    |/
    * 0faba45 Integrate reno
    * a7beb14 (tag: 0.1.0) Add documentation
    * e23b0c8 Add gitignore
    * ff980c7 Initial commit

I only want to show release notes from 1.0.0 onwards, so I configure 'releasenotes/config.yaml' as follows:

    ---
    earliest_version: 1.0.0

If I then build docs, I see the following exception:

    [reno.config] loaded configuration file /tmp/reno-bug-2/releasenotes/config.yaml
    [reno] scanning /tmp/reno-bug-2/releasenotes/notes for current branch release notes
    [reno.scanner] scanning /tmp/reno-bug-2/releasenotes/notes (branch=*current* earliest_version=1.0.0 collapse_pre_releases=True)

    Exception occurred:
      File "/tmp/reno-bug-2/.venv/lib/python2.7/site-packages/reno/scanner.py", line 956, in get_notes_by_version
        earliest_version))
    ValueError: earliest-version set to unknown revision '1.0.0'

Am I doing something wrong? I note that no one is currently using the feature (via codesearch.o.o), suggesting to me it's broken by design.

[Doug Hellmann (doug-hellmann)]

Flags in the config file are applied globally. The earliest-version flag in the config file is probably only useful for projects without branches, or with different configuration files on each branch. If you want to stop scanning on a particular branch, it is possible to set the earliest-version value in the sphinx directive triggering the scan of that branch. That might be more appropriate for your use case.

[Doug Hellmann (doug-hellmann)]

The bug tracker for reno has moved to storyboard: https://storyboard.openstack.org/#!/project/933