$ git clone -n https://src.fedoraproject.org/rpms/perl-Devel-StackTrace.git /var/lib/mock/f45-build-23150-596/root/chroot_tmpdir/scmroot/perl-Devel-StackTrace
Cloning into '/var/lib/mock/f45-build-23150-596/root/chroot_tmpdir/scmroot/perl-Devel-StackTrace'...
$ git fetch origin 4c4640b1f189e12ff1e147294ff89e9a9f639e70:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Devel-StackTrace
 * [new ref]         4c4640b1f189e12ff1e147294ff89e9a9f639e70 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4c4640b Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild