$ git clone -n https://src.fedoraproject.org/rpms/ghc-djinn-lib.git /var/lib/mock/f41-build-side-1-2636648-26251/root/chroot_tmpdir/scmroot/ghc-djinn-lib
Cloning into '/var/lib/mock/f41-build-side-1-2636648-26251/root/chroot_tmpdir/scmroot/ghc-djinn-lib'...
$ git fetch origin b3912c44d68951aa51b770767a044e3f368c37cf:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-djinn-lib
 * [new ref]         b3912c44d68951aa51b770767a044e3f368c37cf -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b3912c4 bump release