$ git clone -n https://src.fedoraproject.org/rpms/ghc-sourcemap.git /var/lib/mock/f45-build-10749-424/root/chroot_tmpdir/scmroot/ghc-sourcemap
Cloning into '/var/lib/mock/f45-build-10749-424/root/chroot_tmpdir/scmroot/ghc-sourcemap'...
$ git fetch origin 55bb46d39ad628e6d9285736d3ca8d408d095656:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-sourcemap
 * [new ref]         55bb46d39ad628e6d9285736d3ca8d408d095656 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 55bb46d Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild