Mnkras was trying to import `git@github.com:php/php-src.git` as a repository, but it was failing with bad credentials.
This should work, and we provide it as an explicit example of a URI which works.
One possible guess is that we like do not preserve `git` properly when used in this way.
More broadly, the repository did not surface the credential failure in a reasonable/clear way.
See also T7106 (this being a problem outside the cluster) and T7221 (similar issues in this vein with the root cause).