It appears git versions older than 2.33 can't handle some simple merges, and many of our CI tasks use such old versions.
The simplest fix is probably to just use GitHub's generated merge branch rather than trying to merge in each CI instance, but I haven't tested it.
We'll probably need to set the merge strategy: https://github.blog/changelog/2022-09-12-merge-commits-now-created-using-the-merge-ort-strategy/
Though, I am not sure if the added complexity to the CI system is worth the rare edge cases.
If it's simply a matter of using origin-pull/N/merge instead of origin-pull/N/head, it doesn't seem that complex?
what is the ref called? This doesn't work:
diff --git a/.cirrus.yml b/.cirrus.yml
index ae962f2906..6cb7253162 100644
--- a/.cirrus.yml
+++ b/.cirrus.yml
@@ -30,8 +30,8 @@ base_template: &BASE_TEMPLATE
- git config --global user.email "ci@ci.ci"
- git config --global user.name "ci"
- if [ "$CIRRUS_PR" = "" ]; then exit 0; fi
- - git fetch $CIRRUS_REPO_CLONE_URL $CIRRUS_BASE_BRANCH
- - git merge FETCH_HEAD # Merge base to detect silent merge conflicts
+ - git fetch $CIRRUS_REPO_CLONE_URL "${CIRRUS_PR}/merge"
+ - git checkout FETCH_HEAD # Use merged changes to detect silent merge conflicts
main_template: &MAIN_TEMPLATE
timeout_in: 120m # https://cirrus-ci.org/faq/#instance-timed-out
Try "pull/${CIRRUS_PR}/merge"