$ git clone -n https://src.fedoraproject.org/rpms/ghc8.10.git /var/lib/mock/f40-build-763212-122451/root/chroot_tmpdir/scmroot/ghc8.10
Cloning into '/var/lib/mock/f40-build-763212-122451/root/chroot_tmpdir/scmroot/ghc8.10'...
$ git fetch origin c33155f966f985288a2c1b1dc9a7257744dd5b3b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc8.10
 * [new ref]         c33155f966f985288a2c1b1dc9a7257744dd5b3b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c33155f use new perfbuild bcond instead of quickbuild/perf_build