Resolve local and remote develop branch conflicts after move from Bitbucket to Github

[bbercoviciUspace]

Hello everyone,

I realized that I had not changed the remote url of the develop branch until this morning. Doing so and running git pull on develop has generated thousands of conflicts, to the point where my local develop branch and the remote one differ quite a bit

Your branch and 'upstream/develop' have diverged,
and have 9632 and 9770 different commits each, respectively.
  (use "git pull" to merge the remote branch into yours)

If I am reading this right, git is treating the two branches as completely different. The last commit on my local develop is

commit 69d6c81f3b7aff7c6d4d04f65454f98a6cc540b5 (HEAD -> develop)
Author: Hanspeter Schaub <hanspeter.schaub@colorado.edu>
Date:   Mon Jan 2 15:09:10 2023 +0000

which is consistent with the state of the bitbucket repo. But this commit doesn't show on the Github commit history. The last commit that the two have in common is 514adef66b57da4d1f06414b491b898c320c6c82 from 2022-12-14.

Could it be that because 69d6c81f3b7aff7c6d4d04f65454f98a6cc540b5 was pushed to bitbucket after the move to Github, I can no longer reconcile my local develop branch and the remote one ?

[bbercoviciUspace]

It appears that the commit IDs were not preserved across the move from Bitbucket to Github. I tried to remove the commit from Jan 2 from my local branch so that the new develop branch strictly included the local commits, but since their IDs are different this is obviously not going to work.

This is quite impactful, because custom branches that were once checked out from develop and periodically rebased or merged against it can no longer be.

[patkenneally]

Correct. This was a necessary result of moving the project to github.com (done to gain access to github's extensive CI/CD capabilities, free to open source projects, and to facilitate community engagement/growth) . Specifically, github.com has a file size limit of 100Mb for files committed to a repo. Anything larger must be committed to git lfs. Prior to the migration, the repo history contained files greater than 100Mb. Those had to be selectively removed, and this necessitated a rewriting of git history. I hope it doesn't take you more than a few hours to migrate your branches. This kind of change is rare in a project, and so we can all rest assured that you won't have to contest with this migration again.

[bbercoviciUspace]

Thanks for the explanation. Keep up the good work 👍

[bbercoviciUspace]

Hi Pat, I've managed to rebase our Basilisk with develop. I created a new remote newBsk pointing to the Github repo, checked out develop at the last commit before the move, created a new branch prepareUspaceBskMergeTest and worked my way up from there. This new branch is the one that's rebased against develop, however I am unable to push it to our own remote :

(utopia_env) benjamin@benjamin-home:~/Development/BSK/basilisk$ git push -f
Enumerating objects: 3077, done.
Counting objects: 100% (3076/3076), done.
Delta compression using up to 12 threads
Compressing objects: 100% (1177/1177), done.
Writing objects: 100% (2306/2306), 873.44 KiB | 45.97 MiB/s, done.
Total 2306 (delta 1703), reused 1575 (delta 1065), pack-reused 0
remote: Resolving deltas: 100% (1703/1703), completed with 491 local objects.
remote: GitLab: LFS objects are missing. Ensure LFS is properly set up or try a manual "git lfs push --all".
To gitlab.com:u-space/gnc/basilisk.git
 ! [remote rejected]     prepareUspaceBskMergeTest -> prepareUspaceBskMergeTest (pre-receive hook declined)
error: failed to push some refs to 'gitlab.com:u-space/gnc/basilisk.git'

I tried git lfs push origin prepareUspaceBskMergeTest, only to be greeted with

Locking support detected on remote "origin". Consider enabling it with:
  $ git config lfs.https://gitlab.com/u-space/gnc/basilisk.git/info/lfs.locksverify true
Unable to find source for object 6e1b277c5f07135a84950604b83e56b736be696a7f3560bcddb1d4aeb944fca1 (try running git lfs fetch --all)

At this stage I must confess that I don't really now what I am doing.

Is it necessary to start from scratch and re-clone the basilisk repository to start anew ?