ERROR: "remote: fatal: fsck error in packed object" when pusing to github

[besi]

Hy there I wanted to migrate from gitlab to github using this project. I was very glad to find out that someone put in some effort to make this easier.

I did run into an issue when pusing the repo using the mirror option:

This is the error I'm getting

remote: fatal: fsck error in packed object
error: remote unpack failed: index-pack failed

This is what I did:

$ git push --no-verify --mirror [email protected]:myusername/project.git

Enter passphrase for key '/Users/myusername/.ssh/id_rsa': 
Enumerating objects: 4680, done.
Counting objects: 100% (4680/4680), done.
Delta compression using up to 8 threads
Compressing objects: 100% (1383/1383), done.
remote: error: object 7e79ae8f47d6d441e380ce0c342d2e27ed1217fbd: duplicateEntries: contains duplicate file entries
remote: fatal: fsck error in packed object
error: remote unpack failed: index-pack failed
To github.com:myusername/project.git
 ! [remote rejected] main (failed)
 ! [remote rejected] 1.0.x -> 1.0.x (failed)
 ! [remote rejected] 1.1.x -> 1.1.x (failed)
 ! [remote rejected] 1.2.3.x -> 1.2.3.x (failed)
 ! [remote rejected] 1.2.x -> 1.2.x (failed)
 ! [remote rejected] develop -> develop (failed)
 ! [remote rejected] master -> master (failed)
 ! [remote rejected] 0.1 -> 0.1 (failed)
 ! [remote rejected] 0.2 -> 0.2 (failed)
 ! [remote rejected] 0.3 -> 0.3 (failed)
 ! [remote rejected] 0.4 -> 0.4 (failed)
 ! [remote rejected] 0.5 -> 0.5 (failed)
 ! [remote rejected] 1.0 -> 1.0 (failed)
error: failed to push some refs to 'github.com:myusername/project.git'

Please note that I created an empty repository on github beforehand.

As I understand this step is mandatory so I do wonder how I may proceed now.
Any help would be greatly appreciated.

[besi]

I did try the following:

1. Delete the repository on github
2. Re-create the repository
3. Change the git url from git@ to https://

 git push --no-verify --mirror https://github.com/myusername/project
Enumerating objects: 4680, done.
Counting objects: 100% (4680/4680), done.
Delta compression using up to 8 threads
Compressing objects: 100% (1383/1383), done.
error: RPC failed; HTTP 500 curl 22 The requested URL returned error: 500
send-pack: unexpected disconnect while reading sideband packet
Writing objects: 100% (4680/4680), 4.41 MiB | 8.51 MiB/s, done.
Total 4680 (delta 3167), reused 4680 (delta 3167), pack-reused 0
fatal: the remote end hung up unexpectedly
Everything up-to-date

Now I am getting a different error as you can see above.