$ git clone -n https://src.fedoraproject.org/rpms/ghc-JuicyPixels.git /var/lib/mock/f38-build-side-42-init-devel-954835-28786/root/chroot_tmpdir/scmroot/ghc-JuicyPixels
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-954835-28786/root/chroot_tmpdir/scmroot/ghc-JuicyPixels'...
$ git fetch origin 6f04192efad3b17242f0c6c095efe6a4a254eb05:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-JuicyPixels
 * [new ref]         6f04192efad3b17242f0c6c095efe6a4a254eb05 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6f04192 Convert to %autorelease and %autochangelog