Flutter `master` channel is broken on `flutter/codelabs` CI

[domesticmouse]

I'm seeing the following behavior only on the master channel of my flutter/codelabs CI:

  dart --version
  shell: /usr/bin/bash --noprofile --norc -e -o pipefail {0}
  env:
    JAVA_HOME: /opt/hostedtoolcache/Java_Zulu_jdk/17.0.1[3](https://github.com/flutter/codelabs/actions/runs/12401981182/job/34622521206#step:5:3)-11/x64
    JAVA_HOME_17_X64: /opt/hostedtoolcache/Java_Zulu_jdk/17.0.13-11/x6[4](https://github.com/flutter/codelabs/actions/runs/12401981182/job/34622521206#step:5:4)
    FLUTTER_ROOT: /opt/hostedtoolcache/flutter/master-any-x64
    PUB_CACHE: /home/runner/.pub-cache
fatal: Not a valid object name upstream/master

Full context: https://github.com/flutter/codelabs/actions/runs/12401981182/job/34622521206

[domesticmouse]

You can see the various attempts to fix this breakage in flutter/codelabs#2273

[jtmcdole]

fatal: Not a valid object name upstream/master

We calculate the engine hash based on the difference between upstream/master and HEAD. Is your upstream origin?

[domesticmouse]

This is happening in CI, so it's subosito/flutter-action pulling a Flutter channel in the CI bot. That repo does checks for stable, beta, and master on linux, macos and windows hosts.

[jtmcdole]

Yep; master doesn't work because it can't find the HASH for the engine because almost assuredly action is checking out with origin vs upstream

[domesticmouse]

So subosito/flutter-action needs to be fixed?

[jtmcdole]

No - I think we could fix this by testing for upstream vs origin:

git remote get-url upstream

I'm looking deeper.

[a-h-mzd]

This also happens on local machines and is not exclusive to CI tools. #160552

[jtmcdole]

We're aware and making a change