$ git clone -n https://src.fedoraproject.org/rpms/perl-Authen-Credential.git /var/lib/mock/f45-build-21789-588/root/chroot_tmpdir/scmroot/perl-Authen-Credential
Cloning into '/var/lib/mock/f45-build-21789-588/root/chroot_tmpdir/scmroot/perl-Authen-Credential'...
$ git fetch origin 055d1d2ebf6f772c48523ead87932499edfbedf0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Authen-Credential
 * [new ref]         055d1d2ebf6f772c48523ead87932499edfbedf0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 055d1d2 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild