Can not merge pull requests after approval due to The merge-base changed after approval.

[dgokcin]

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Hello

Yesterday we noticed that there is a weird message appearing when a PR is approved. We have a feature branch created from main and we are trying to merge it to develop. Once the PR is approved and required checks pass, we see this message suggesting that the merge-base has changed after approval, although it has not.

This has a significant impact on developer experience, so I kindly ask for your support/guidance.

Thanks

[cmhanthorn]

I ran into the same problem. In my case I had issued the pull request and requested a review from someone, then before they got to it I pushed a new commit removing some commented code.

It seems to be related to these security enhancement changes: https://github.blog/changelog/2023-06-06-security-enhancements-to-required-approvals-on-pull-requests/. Since I am an org owner I was able to look at the branch protection settings and saw the setting in the image below.

After I deselected this setting my reviewer was able to approve the PR and merge the changes.

From the wording of the setting I think even with it enabled it should have allowed my reviewer to approve and merge the changes, since I made the later commit before he did the review. I think this is a bug.

[dgokcin]

I also think this is a bug since closing the pr and re-openning it caused the issue to go away without changing any repository settings.

[JonMoore46]

Not sure if this will help anyone but I've just had this happen on a branch where I had branched off from an existing branch (didn't mean to do this......) and then the first brach was merged into master/main.

This seemed to trigger the message appearing.

[adrian-izdebski-lrn]

It looks like the pointer to the baseline branch is fixed in a PR, but then there is some process to check that sha. It fails because the baseline tip moved.
It's not the best behaviour.
Reopening PRs is an unwelcome workaround.

---

You can edit a PR and change a baseline from e.g. staging to .... staging, which will fix this without opening another PR.

[rogerfernandes]

This works for me! Thanks!

[chris-troupe]

This worked for me as well, I would recommend trying this as the first solution.

[davidicus]

This also worked for me! Thanks.

[Duncan-hrn]

Also getting this happening:

• PR1->develop opened and 1x approved (not merged)
• some other PR is merged to develop
• PR1 approval is now dismissed with message "The merge-base changed after approval."

[tobalsgithub]

We're hitting this now too. Strangely, I turned off the Dismiss stale pull request setting, and now the reviews aren't getting dismissed, but the PR still acts like no one has approved. Closing and re-opening the PR was the only thing that allowed us to move forward.

[adeshmukh-legion]

Closing and reopening the PR did the trick, thanks!

[robindubeyibm]

Yep, Closing and reopening the PR worked. Thanks

[alexmitelman]

Happens to me too. Auto-dismisses my review without any new code.

[jcook-uptycs]

Saw this as well with commits and PR created on Aug 7, 2023.

As soon as a new review was added the review would be dismissed with the message

The merge-base changed after approval.
It was done as if the PR author performed the action themself. (Which they didn't)

Closing the PR and re-opening it did fix the issue.

We do have dismiss stale reviews enabled, but no new commits were added.

[BSmith-87]

We are experiencing this same issue. It requires closing and opening the PR, or having somebody with admin permissions to override the required approval. (Turning off dismiss stale approvals is not something we are willing to do)

According to the git history, there were no commits that triggered this condition.

[dickinr]

I'm experiencing this as well. Can't find a rhyme or reason to it. I'll approve a pull and it will immediately be dismissed seconds later. There aren't any new commits being pushed.

[Penagwin]

We are also seeing this. My PR is from my branch -> dev. The last commit to both master/dev was over an hour ago, and my last commit on my branch was over 30 minutes ago (I double checked). Every review said "Dismissed - The merge-base changed after approval."

• Coworker 1 - 29 minutes ago
• Coworker 2 - 22 minutes ago
• Coworker 3 - 8 minutes ago

[hyungmok]

In my case, I could merge my PR after adding members on the Collaborators and Teams page in Settings. Just FYI.

[rafaelrezend]

In my case, I could merge my PR after adding members on the Collaborators and Teams page in Settings. Just FYI.

This comment was marked as off-topic, but actually this is exactly what worked for me.

My colleague was able to approve my PR because he was part of the Organization. His approval was ignored until I added our Team as a Collaborator in the repo (which I missed earlier). His approval immediately got the green badge as well as the PR.

[akloss-cibo]

Just a "me too" on this. A PR was stuck like this, pushed another branch name (of the same commit) and it approved and merged successfully. If anyone from GitHub actually wants to try to fix, I have left the "dead" PR open. Feel free to reach out.

[duelyy]

Disabling the branch protection for "Dismiss stale pull request approvals when new commits are pushed" allowed us to get pass the message, "the merge-base changed after approval". This is a weird bug because nobody has made any new commits to our PR and it's annoying because it happens randomly.

Any chance that Github Support can investigate this bug?

[Triblo]

Just another person on a team experiencing this bug!

[hanseltime]

+1 for my org as well. This can be a productivity killer

[jpicht]

Bump. Happening to my org as well.

[AngieWongHeb]

same here

[MarkJacksonRG]

Bump. This happened to me today. It's a time waster. Please fix it. Thanks in advance

[henryvincent1]

We're also experiencing this. It can unduly disrupt our release cycle. Please fix, thanks!

[matthewstyler]

Bump

[AronPhillimorePS]

Bump

[yiyuan-zhang]

Bump

[TheQueenIsDead]

Can you please stop bumping this issue and just upvote instead? I am tired of receiving a notification and thinking progress has been made / a new insightful comment has been added, only to find it's another troglodyte with a GitHub account.

[agucollado]

This doesn't sounds like an issue, but the intended purpose of the check.
After doing a rebase from the base branch (and resolving any conflict that shows up during the rebase) solved the problem and reviews are no longer dismissed

[akloss-cibo]

Some of us observe that reviews are dismissed continuously; that is, someone approves, and then GitHub immediately repeats the message and dismisses the review even though the base isn't changing again. At least in my experience, the PR is, AFAIK, permanently "dead" at this point, and needs to be replaced with a new one.

[sam-netlogix]

Some of us observe that reviews are dismissed continuously; that is, someone approves, and then GitHub immediately repeats the message and dismisses the review even though the base isn't changing again. At least in my experience, the PR is, AFAIK, permanently "dead" at this point, and needs to be replaced with a new one.

@akloss-cibo we observed the same behaviour

[wkhadgar]

someone approves, and then GitHub immediately repeats the message and dismisses the review even though the base isn't changing again

That's the exact issue, the first time the message is thrown is pretty much valid, but after re-approval, it SHOULD solve the issue and re-enable merging (provided you're not doing anything with the base). This is currently wrong, and having to resort to those gimmicks of closing and reopening PRs is really unprofessional and bad looking.

I really hope GitHub team fix this up asap.

[peterhadlaw]

Bump

[sanmeet89]

I am also facing the same issue and it definitely looks like a bug. Can anyone from Github team look into this?

[lucaspopp-wbd]

Still experiencing this

[markalanevans]

+1 you can't stack branches and easily approve and move through PR's with this feature enabled.