Removing CODEOWNERS file form not master branch fails

[maciej-karas-form3]

Context

I was trying to prepare to archive a repo fork-bc-java by following steps in archiving instructions. The first step requires to add prepare_archive = true property to aforementioned repository resource in infrastructure-github and it was done in PR. TFE plan succeeded but apply failed with an error:

POST https://api.github.com/repos/form3tech/fork-bc-java/git/trees: 502 Server Error 

After manually removing CODEOWNERS file in fork-bc-java repo apply succeeds.

Possible cause

It seems that this issue is occurring when the repo doesn't have master branch as a default one. fork-bc-java uses form3-patch as a default branch and master branch does not exists and doesn't contain CODEOWNERS file.