$ git clone -n https://src.fedoraproject.org/rpms/rubygem-bcrypt.git /var/lib/mock/f45-build-34796-691/root/chroot_tmpdir/scmroot/rubygem-bcrypt
Cloning into '/var/lib/mock/f45-build-34796-691/root/chroot_tmpdir/scmroot/rubygem-bcrypt'...
$ git fetch origin a3aa63399f3259a23cb12b4a11f5a97d60ce4d4f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-bcrypt
 * [new ref]         a3aa63399f3259a23cb12b4a11f5a97d60ce4d4f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a3aa633 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild