comm-central revision fails to apply, checkout points to revision which should let it apply

[Archaeopteryx]

https://phabricator.services.mozilla.com/D247833 is a revision for comm-central and failed with:

unable to find 'rust/ews_xpcom/src/safe_xpcom/folder_callbacks.rs' for patching
(use '--prefix' to apply patch relative to the current directory)
1 out of 1 hunks FAILED -- saving rejects to file rust/ews_xpcom/src/safe_xpcom/folder_callbacks.rs.rej
patching file rust/ews_xpcom/src/client.rs
Hunk #1 FAILED at 749
1 out of 1 hunks FAILED -- saving rejects to file rust/ews_xpcom/src/client.rs.rej
patching file mailnews/test/fakeserver/EwsServer.sys.mjs
Hunk #1 FAILED at 150
Hunk #2 FAILED at 370
Hunk #3 FAILED at 491
3 out of 3 hunks FAILED -- saving rejects to file mailnews/test/fakeserver/EwsServer.sys.mjs.rej
patching file mailnews/protocols/ews/test/unit/test_folder_sync.js
Hunk #1 FAILED at 15
Hunk #2 FAILED at 70
Hunk #3 FAILED at 148
3 out of 3 hunks FAILED -- saving rejects to file mailnews/protocols/ews/test/unit/test_folder_sync.js.rej
patching file mailnews/protocols/ews/src/IEwsClient.idl
Hunk #1 FAILED at 127
1 out of 1 hunks FAILED -- saving rejects to file mailnews/protocols/ews/src/IEwsClient.idl.rej
patching file mailnews/protocols/ews/src/EwsIncomingServer.h
Hunk #1 FAILED at 35
1 out of 1 hunks FAILED -- saving rejects to file mailnews/protocols/ews/src/EwsIncomingServer.h.rej
patching file mailnews/protocols/ews/src/EwsIncomingServer.cpp
Hunk #1 succeeded at 46 with fuzz 2 (offset -7 lines).
Hunk #2 FAILED at 152
Hunk #3 FAILED at 320
2 out of 3 hunks FAILED -- saving rejects to file mailnews/protocols/ews/src/EwsIncomingServer.cpp.rej
abort: patch failed to apply

From the papertrail logs:

May 13 07:57:14 [34.168.63.134](https://my.papertrailapp.com/systems/14334829172/events?focus=1858961720421261321&selected=1858961720421261321) [code-review/production/bot](https://my.papertrailapp.com/groups/16151392/events?q=program%3Acode-review%2Fproduction%2Fbot&focus=1858961720421261321&selected=1858961720421261321) 2025-05-13 14:57:14 mercurial.py: [info     ] Mercurial                      stdout=b'searching for changes\n' 
May 13 07:57:14 [34.168.63.134](https://my.papertrailapp.com/systems/14334829172/events?focus=1858961720425455620&selected=1858961720425455620) [code-review/production/bot](https://my.papertrailapp.com/groups/16151392/events?q=program%3Acode-review%2Fproduction%2Fbot&focus=1858961720425455620&selected=1858961720425455620) 2025-05-13 14:57:14 mercurial.py: [info     ] Mercurial                      stdout=b'no changes found\n' 
May 13 07:57:14 [34.168.63.134](https://my.papertrailapp.com/systems/14334829172/events?focus=1858961721868296193&selected=1858961721868296193) [code-review/production/bot](https://my.papertrailapp.com/groups/16151392/events?q=program%3Acode-review%2Fproduction%2Fbot&focus=1858961721868296193&selected=1858961721868296193) 2025-05-13 14:57:14 mercurial.py: [info     ] Mercurial                      stdout=b'added 0 pushes\n' 
May 13 07:57:14 [34.168.63.134](https://my.papertrailapp.com/systems/14334829172/events?focus=1858961721922822157&selected=1858961721922822157) [code-review/production/bot](https://my.papertrailapp.com/groups/16151392/events?q=program%3Acode-review%2Fproduction%2Fbot&focus=1858961721922822157&selected=1858961721922822157) 2025-05-13 14:57:14 mercurial.py: [info     ] Mercurial                      stdout=b'515784f7097e comm\n' 
May 13 07:57:14 [34.168.63.134](https://my.papertrailapp.com/systems/14334829172/events?focus=1858961721927016449&selected=1858961721927016449) [code-review/production/bot](https://my.papertrailapp.com/groups/16151392/events?q=program%3Acode-review%2Fproduction%2Fbot&focus=1858961721927016449&selected=1858961721927016449) 2025-05-13 14:57:14 mercurial.py: [info     ] Stopping at revision 515784f7097e48e5587c72a75ed1727eb43d4656 
May 13 07:57:14 [34.168.63.134](https://my.papertrailapp.com/systems/14334829172/events?focus=1858961721927016453&selected=1858961721927016453) [code-review/production/bot](https://my.papertrailapp.com/groups/16151392/events?q=program%3Acode-review%2Fproduction%2Fbot&focus=1858961721927016453&selected=1858961721927016453) 2025-05-13 14:57:14 mercurial.py: [info     ] Updating repo to revision tip  
May 13 07:57:15 [34.168.63.134](https://my.papertrailapp.com/systems/14334829172/events?focus=1858961722648436738&selected=1858961722648436738) [code-review/production/bot](https://my.papertrailapp.com/groups/16151392/events?q=program%3Acode-review%2Fproduction%2Fbot&focus=1858961722648436738&selected=1858961722648436738) 2025-05-13 14:57:15 mercurial.py: [info     ] Mercurial                      stdout=b'0 files updated, 0 files merged, 0 files removed, 0 files unresolved\n' 
May 13 07:57:15 [34.168.63.134](https://my.papertrailapp.com/systems/14334829172/events?focus=1858961723323719682&selected=1858961723323719682) [code-review/production/bot](https://my.papertrailapp.com/groups/16151392/events?q=program%3Acode-review%2Fproduction%2Fbot&focus=1858961723323719682&selected=1858961723323719682) 2025-05-13 14:57:15 mercurial.py: [info     ] Updated repo                   repo=comm-central revision=tip 
May 13 07:57:15 [34.168.63.134](https://my.papertrailapp.com/systems/14334829172/events?focus=1858961723323719710&selected=1858961723323719710) [code-review/production/bot](https://my.papertrailapp.com/groups/16151392/events?q=program%3Acode-review%2Fproduction%2Fbot&focus=1858961723323719710&selected=1858961723323719710) 2025-05-13 14:57:15 mercurial.py: [info     ] Applying patch                 message='Bug 1956568 - Process folder updates during sync. r=babolivier,#thunderbird-back-end-reviewers\n\nSummary:\n\nDifferential Revision: https://phabricator.services.mozilla.com/D247833\n\nTest Plan:\n\nReviewers: babolivier, #thunderbird-back-end-reviewers\n\nSubscribers:\n\nBug #: 1956568\nDifferential Diff: PHID-DIFF-pzzgact4bcc6i3boicvl' phid=PHID-DIFF-pzzgact4bcc6i3boicvl 
May 13 07:57:15 [34.41.193.81](https://my.papertrailapp.com/systems/14334787515/events?focus=1858961723818647572&selected=1858961723818647572) [code-review/production/bot](https://my.papertrailapp.com/groups/16151392/events?q=program%3Acode-review%2Fproduction%2Fbot&focus=1858961723818647572&selected=1858961723818647572) 2025-05-13 14:57:15 workflow.py: [info     ] Updated HarborMaster status    revision=PHID-DIFF-mcr626teh3d6eooq3xvx state=<BuildState.Pass: 'pass'> 
May 13 07:57:15 [34.41.193.81](https://my.papertrailapp.com/systems/14334787515/events?focus=1858961723835424791&selected=1858961723835424791) [code-review/production/bot](https://my.papertrailapp.com/groups/16151392/events?q=program%3Acode-review%2Fproduction%2Fbot&focus=1858961723835424791&selected=1858961723835424791) 2025-05-13 14:57:15 stats.py: [warning  ] InfluxDb client not connected: metrics will not be reported 
May 13 07:57:15 [34.168.63.134](https://my.papertrailapp.com/systems/14334829172/events?focus=1858961723973836807&selected=1858961723973836807) [code-review/production/bot](https://my.papertrailapp.com/groups/16151392/events?q=program%3Acode-review%2Fproduction%2Fbot&focus=1858961723973836807&selected=1858961723973836807) 2025-05-13 14:57:15 mercurial.py: [info     ] Mercurial                      stdout=b'applying patch from stdin\n' 
May 13 07:57:15 [34.168.63.134](https://my.papertrailapp.com/systems/14334829172/events?focus=1858961724082888706&selected=1858961724082888706) [code-review/production/bot](https://my.papertrailapp.com/groups/16151392/events?q=program%3Acode-review%2Fproduction%2Fbot&focus=1858961724082888706&selected=1858961724082888706) 2025-05-13 14:57:15 mercurial.py: [info     ] Mercurial                      stderr=b"unable to find 'rust/ews_xpcom/src/safe_xpcom/folder_callbacks.rs' for patching\n"

The mentioned revision https://hg-edge.mozilla.org/comm-unified/rev/515784f7097e48e5587c72a75ed1727eb43d4656 is from today.
The file reported as missing landed last Friday in https://bugzilla.mozilla.org/show_bug.cgi?id=1964793
@marco-c Any idea why the review bot could be on an outdated revision?

[kaie]

it seems that the review-bot uses the "tip" of comm-unified, which in this case points to the wrong branch (a stable comm-esr128 branch).

The simplest solution would be to always use the default branch.

[eleanxr]

One thing I'm kind of confused about is how seeing failures like this isn't more prevalent. If the review bot is by default pointing at an ESR branch, then I'd think patches would be failing all of the time since we're all building on comm-central by default.

[kaie]

comm-unified is a consolidation of all branches, AIUI.

In mercurial, the most recent commit automatically is the "tip", regardless of which branch it is landed into.

Because we're frequently commiting into comm-central, it works most of the time.

Only if we're doing a backport commit on a stable branch, the systems would misbehave until the next comm-central commit.

[eleanxr]

If I'm reading the code correctly, it looks like maybe Hg checkouts default to tip (

code-review/integration/run.py

Line 68 in d417178

def clone(url, directory, branch="tip"):

) ? In which case, maybe there's specific config for comm-central that we need to put somewhere to get the review bot onto the right branch.

[eleanxr]

Querying within the TB team, it seems that #2042 may be related.

[marco-c]

Normally the bot takes the base changeset from the Phabricator revision, but we've had to temporarily disable it because of the migration from hg to git: mozilla/libmozevent#111.

There are two options:

1. switch to comm-central for now (or something akin to autoland, if it exists for comm), until we can turn back base changeset identification for all repos;
2. add a setting to enable/disable base revision identification, and enable it for comm-*. Then when we can turn back base changeset identification for all repos we'll remove this setting.

[Archaeopteryx]

The configuration has been updated to use https://hg.mozilla.org/comm-central/ as repository. Please mention if the issue is still observed.