Travis CI deployment logs "fatal" error, yet it's actually harmless

[hroncok]

fatal: ambiguous argument 'refs/remotes/origin/gh-pages': unknown revision or path not in the working tree.
Use '--' to separate paths from revisions, like this:
'git <command> [<revision>...] -- [<file>...]'
Error: git push failed (exit status 128).
Note: Due to security constraints, Elsa does not show the error message from git, as it may include sensitive information and this could be logged. Use the --show-git-push-stderr switch to change this behavior.
Setting up git...
Rewriting gh-pages branch...
Pushing to GitHub...
Script failed with status 128

I blame 2be014e50b7e7be8ad2f0d37f6d543c319b145fe + ba0fc9eab446691a95b70b7c7a77088b50df4059

[hroncok]

Oh, so the error on python.cz was different. But the fatal error message appears to exist in all Travis deploy logs, even tough it's actually non-fatal:

Deploying application
fatal: ambiguous argument 'refs/remotes/origin/gh-pages': unknown revision or path not in the working tree.
Use '--' to separate paths from revisions, like this:
'git <command> [<revision>...] -- [<file>...]'
Setting up git...
Rewriting gh-pages branch...
Pushing to GitHub...
Done. Your build exited with 0.

We should suppress it, it's confusing.

[honzajavorek]

It is confusing. I'm debugging why python.cz deploys fail, I searched for the error message, and now I'm seeing it's irrelevant to the issue 😄