GitHub GMT.jl documentation broken and have no idea on how to fix

I’m totally lost on why the documentation of GMT.jl is now broken. Problems start to arise when, for some unknown reason the Linux CI build started to fail.

ERROR: LoadError: could not load library "/home/runner/gmt-install-dir/lib/"
/opt/hostedtoolcache/julia/1.7.1/x64/bin/../lib/julia/ cannot allocate memory in static TLS block

Then I added a Mac build and at least the tests kept running. But later started problems with the documentation not being updated, which ended on the current “404 No Github pages here”. But when I look at the gh-pages branch everything is there as it should.

Recent commits are not even able to push the documentation. I see this error that clearly seems the culprit:

hint: 	git branch -m <name>
Warning: Permanently added the RSA host key for IP address '' to the list of known hosts. Permission denied (publickey).
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.
┌ Error: Git failed to fetch
│ This can be caused by a DOCUMENTER_KEY variable that is not correctly set up.
│ Make sure that the environment variable is properly set up as a Base64-encoded string
│ of the SSH private key. You may need to re-generate the keys with DocumenterTools.
└ @ Documenter ~/.julia/packages/Documenter/Nu7Lp/src/Documenter.jl:613
┌ Error: Failed to push:
│   exception =
│    failed process: Process(`git fetch upstream`, ProcessExited(128)) [128]

But I already regenerated the deploying key two times and nothing changed. And furthermore, looking at the key at the settings it says it was never used

Any idea on what to do?

Just to inform that, with some luck, I solved this.
First problem (the keys) was that when I updated the Deploy key I forgot to update also the private key in secrets.

The hardest one was the There is no GitHub pages here when that was in fact WRONG. It turned out, and this is the bit of valuable information for others, the problem was that the gh-pages branch was too big because of the push_preview = true in make.jl deploydocs. I latter found out that bDocumenter.jl manual warns about this but even the solution advanced there didn’t work because of a timeout error.

Moral of the history (as we say here), don’t let your gh-pages branch get too big (whatever that is).