$ git clone -n https://src.fedoraproject.org/rpms/ghc-concurrent-output.git /var/lib/mock/f41-build-side-1-2636562-26242/root/chroot_tmpdir/scmroot/ghc-concurrent-output
Cloning into '/var/lib/mock/f41-build-side-1-2636562-26242/root/chroot_tmpdir/scmroot/ghc-concurrent-output'...
$ git fetch origin 7fbbb54d42c1a044f69f4ec1b6facd96d8a8d381:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-concurrent-output
 * [new ref]         7fbbb54d42c1a044f69f4ec1b6facd96d8a8d381 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7fbbb54 https://hackage.haskell.org/package/concurrent-output-1.10.21/changelog