$ git clone -n https://src.fedoraproject.org/rpms/perl-ExtUtils-Builder.git /var/lib/mock/f45-build-23360-597/root/chroot_tmpdir/scmroot/perl-ExtUtils-Builder
Cloning into '/var/lib/mock/f45-build-23360-597/root/chroot_tmpdir/scmroot/perl-ExtUtils-Builder'...
$ git fetch origin 16054f2a79d43f66ce6929cf7328fb6279a20d3e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-ExtUtils-Builder
 * [new ref]         16054f2a79d43f66ce6929cf7328fb6279a20d3e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 16054f2 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild