$ git clone -n https://src.fedoraproject.org/rpms/ghc-dotgen.git /var/lib/mock/f45-build-10232-414/root/chroot_tmpdir/scmroot/ghc-dotgen
Cloning into '/var/lib/mock/f45-build-10232-414/root/chroot_tmpdir/scmroot/ghc-dotgen'...
$ git fetch origin 4cf90d379ac6183bd28b10ee3584f31bd9e6e2c8:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-dotgen
 * [new ref]         4cf90d379ac6183bd28b10ee3584f31bd9e6e2c8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4cf90d3 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild