running this merge-automation action task on mozilla-release (90.0) or mozilla-beta (91.0) I end up with the same error:

2021-07-26 21:30:49,617 - scriptworker_client.utils - INFO - Running ['hg', 'up', '-C', 'esr91', '-R', '/app/workdir/src'] in /app ...
2021-07-26 21:30:55,429 - scriptworker_client.utils - INFO - 138 files updated, 0 files merged, 10 files removed, 0 files unresolved
2021-07-26 21:30:55,485 - scriptworker_client.utils - INFO - ['hg', 'up', '-C', 'esr91', '-R', '/app/workdir/src'] in /app exited 0
2021-07-26 21:30:55,486 - treescript.versionmanip - INFO - Reading /app/workdir/src/browser/config/version.txt for version information.
2021-07-26 21:30:55,487 - treescript.versionmanip - INFO - Contents:
2021-07-26 21:30:55,487 - treescript.versionmanip - INFO -  91.0
2021-07-26 21:30:55,489 - scriptworker_client.utils - INFO - Running ['hg', 'identify', '-r', 'esr91', '--template', '{node}', '-R', '/app/workdir/src'] in /app ...
2021-07-26 21:30:55,878 - scriptworker_client.utils - INFO - 26ce397b6ae1874c007bc18e13d655bab15da59b
2021-07-26 21:30:55,879 - scriptworker_client.utils - INFO - ['hg', 'identify', '-r', 'esr91', '--template', '{node}', '-R', '/app/workdir/src'] in /app exited 0
2021-07-26 21:30:55,881 - scriptworker_client.utils - INFO - Running ['hg', 'up', '-C', 'release', '-R', '/app/workdir/src'] in /app ...
2021-07-26 21:31:25,631 - scriptworker_client.utils - INFO - 17154 files updated, 0 files merged, 3277 files removed, 0 files unresolved
2021-07-26 21:31:25,691 - scriptworker_client.utils - INFO - ['hg', 'up', '-C', 'release', '-R', '/app/workdir/src'] in /app exited 0
2021-07-26 21:31:25,693 - scriptworker_client.utils - INFO - Running ['hg', 'identify', '-r', 'release', '--template', '{node}', '-R', '/app/workdir/src'] in /app ...
2021-07-26 21:31:26,093 - scriptworker_client.utils - INFO - 573faf0dec2460a8a25bf567fa0ff26df4dcff0c
2021-07-26 21:31:26,094 - scriptworker_client.utils - INFO - ['hg', 'identify', '-r', 'release', '--template', '{node}', '-R', '/app/workdir/src'] in /app exited 0
2021-07-26 21:31:26,095 - treescript.versionmanip - INFO - Reading /app/workdir/src/browser/config/version.txt for version information.
2021-07-26 21:31:26,096 - treescript.versionmanip - INFO - Contents:
2021-07-26 21:31:26,096 - treescript.versionmanip - INFO -  90.0.3
2021-07-26 21:31:26,097 - scriptworker_client.utils - INFO - Running ['hg', 'tag', '-m', 'No bug - tagging 573faf0dec2460a8a25bf567fa0ff26df4dcff0c with FIREFOX_ESR_90_BASE a=release DONTBUILD CLOSED TREE', '-r', '573faf0dec2460a8a25bf567fa0ff26df4dcff0c', '-f', 'FIREFOX_ESR_90_BASE', '-R', '/app/workdir/src'] in /app ...
2021-07-26 21:31:35,981 - scriptworker_client.utils - INFO - ['hg', 'tag', '-m', 'No bug - tagging 573faf0dec2460a8a25bf567fa0ff26df4dcff0c with FIREFOX_ESR_90_BASE a=release DONTBUILD CLOSED TREE', '-r', '573faf0dec2460a8a25bf567fa0ff26df4dcff0c', '-f', 'FIREFOX_ESR_90_BASE', '-R', '/app/workdir/src'] in /app exited 0
2021-07-26 21:31:35,983 - scriptworker_client.utils - INFO - Running ['hg', 'identify', '-r', '.', '--template', '{node}', '-R', '/app/workdir/src'] in /app ...
2021-07-26 21:31:36,535 - scriptworker_client.utils - INFO - 8e3136d7b4f2935937dd3935382a817cd8f74767
2021-07-26 21:31:36,536 - scriptworker_client.utils - INFO - ['hg', 'identify', '-r', '.', '--template', '{node}', '-R', '/app/workdir/src'] in /app exited 0
2021-07-26 21:31:36,538 - treescript.merges - INFO - Rebranding release to esr91
2021-07-26 21:31:36,538 - treescript.versionmanip - INFO - Reading /app/workdir/src/browser/config/version.txt for version information.
2021-07-26 21:31:36,538 - treescript.versionmanip - INFO - Contents:
2021-07-26 21:31:36,538 - treescript.versionmanip - INFO -  90.0.3
2021-07-26 21:31:36,539 - treescript.versionmanip - INFO - Reading /app/workdir/src/browser/config/version_display.txt for version information.
2021-07-26 21:31:36,539 - treescript.versionmanip - INFO - Contents:
2021-07-26 21:31:36,539 - treescript.versionmanip - INFO -  90.0.3
2021-07-26 21:31:36,540 - treescript.merges - INFO - New version is 90.0.3esr
2021-07-26 21:31:36,540 - treescript.versionmanip - INFO - Reading /app/workdir/src/browser/config/version_display.txt for version information.
2021-07-26 21:31:36,540 - treescript.versionmanip - INFO - Contents:
2021-07-26 21:31:36,540 - treescript.versionmanip - INFO -  90.0.3
Traceback (most recent call last):
  File "/app/bin/treescript", line 8, in <module>
    sys.exit(main())
  File "/app/lib/python3.8/site-packages/treescript/script.py", line 132, in main
    return sync_main(async_main, default_config=get_default_config())
  File "/app/lib/python3.8/site-packages/scriptworker_client/client.py", line 127, in sync_main
    loop.run_until_complete(_handle_asyncio_loop(async_main, config, task))
  File "/usr/local/lib/python3.8/asyncio/base_events.py", line 616, in run_until_complete
    return future.result()
  File "/app/lib/python3.8/site-packages/scriptworker_client/client.py", line 182, in _handle_asyncio_loop
    await async_main(config, task)
  File "/app/lib/python3.8/site-packages/treescript/script.py", line 105, in async_main
    await retry_async(do_actions, args=(config, task, actions_to_perform, repo_path), retry_exceptions=(CheckoutError, PushError))
  File "/app/lib/python3.8/site-packages/scriptworker_client/aio.py", line 322, in retry_async
    return await func(*args, **kwargs)
  File "/app/lib/python3.8/site-packages/treescript/script.py", line 68, in do_actions
    await perform_merge_actions(config, task, actions, repo_path, repo_type)
  File "/app/lib/python3.8/site-packages/treescript/script.py", line 39, in perform_merge_actions
    push_activity = await do_merge(config, task, repo_path)
  File "/app/lib/python3.8/site-packages/treescript/merges.py", line 236, in do_merge
    await apply_rebranding(config, repo_path, merge_config)
  File "/app/lib/python3.8/site-packages/treescript/merges.py", line 112, in apply_rebranding
    await do_bump_version(config, repo_path, [version_config["filename"]], create_new_version(version_config, repo_path))
  File "/app/lib/python3.8/site-packages/treescript/versionmanip.py", line 130, in do_bump_version
    next_version = VersionClass.parse(saved_next_version)
  File "/app/lib/python3.8/site-packages/mozilla_version/gecko.py", line 228, in parse
    return super(GeckoVersion, cls).parse(
  File "/app/lib/python3.8/site-packages/mozilla_version/version.py", line 56, in parse
    return cls(**kwargs)
  File "<attrs generated init mozilla_version.gecko.GeckoVersion>", line 15, in __init__
  File "/app/lib/python3.8/site-packages/mozilla_version/gecko.py", line 484, in __attrs_post_init__
    super(_VersionWithEdgeCases, self).__attrs_post_init__()
  File "/app/lib/python3.8/site-packages/mozilla_version/gecko.py", line 223, in __attrs_post_init__
    raise PatternNotMatchedError(self, patterns=error_messages)
mozilla_version.errors.PatternNotMatchedError: "90.0.3esr" does not match the pattern: "90" is not a valid ESR major number. Valid ones are: (10, 17, 24, 31, 38, 45, 52, 60, 68, 78)
exit code: 1

some how we end up with 90 as the major number, but even if it were 91, it isn't in the list.

I am not sure if this is in-tree, a ship-it issue, or a mozilla-version issue.

as this takes the version from mozilla-release, I think it is best to deal with this after we release and after we merge beta->release and solve any problems in the creation of esr91 then.

mozilla_version already has a fix for this: https://github.com/mozilla-releng/mozilla-version/commit/1b789c5e9587e5f43c7b858d369fc43e9f334397

this was resolved with scriptworker change to pick up the new version of mozilla_version and merging mozilla_version to production.

https://github.com/mozilla-releng/scriptworker-scripts/commit/163da9fbfd12e89e057c680ebf5152d6c64654d5
https://github.com/mozilla-releng/mozilla-version/commit/1b789c5e9587e5f43c7b858d369fc43e9f334397