794333 - Updates builder doesn't handle push race in tools repo

Status: RESOLVED WONTFIX

(Release Engineering :: Release Automation: Other, defect)

Description

[Nick Thomas [:nthomas] (UTC+12)]

I'd pushed to tools between the updates builder cloning and pushing the bumped configs back. The error was:

retry: Calling <function run_with_timeout at 0xb7cd1294> with args: (['hg', 'push', '-e', 'ssh -l tbirdbld -i ~cltbld/.ssh/tbirdbld_dsa', '-f', 'ssh://hg.mozilla.org/build/tools'], 1260, None, None, False, True), kwargs: {}, attempt #1
Executing: ['hg', 'push', '-e', 'ssh -l tbirdbld -i ~cltbld/.ssh/tbirdbld_dsa', '-f', 'ssh://hg.mozilla.org/build/tools']
pushing to ssh://hg.mozilla.org/build/tools
searching for changes
remote: Warning: Permanently added the RSA host key for IP address '63.245.215.25' to the list of known hosts.
remote: adding changesets
remote: adding manifests
remote: adding file changes
remote: added 2 changesets with 6 changes to 6 files (+1 heads)
remote: You may not push multiple heads to this repository.
remote: transaction abort!
remote: rollback completed
remote: abort: pretxnchangegroup.a_singlehead hook exited with status 1

Options:
* add rebase + repush logic
* WONTFIX, since this seems to be extremely rare and is easily resolved by rebuilding the updates builder

Comment 1

[[e-mail] (:bhearsum)]

Because this a buildbot Factory rather than a script, adding rebase/push logic is tough/painful. This builder also goes away when Balrog is in production. Because of both of those reasons and yours, I think WONTFIX'ing this is OK.

Comment 2

[[e-mail] (:bhearsum)]

This became an issue when trying to fix bug 1105485. I ended up adding an extra "hg pull" and "hg update" step right before commiting config changes. This greatly reduces the chance of racing, but doesn't eliminate it fully. Hopefully that will get us along well enough until this code goes away.