$ git clone -n https://src.fedoraproject.org/rpms/ghc-base16-bytestring.git /var/lib/mock/f39-build-1507021-35220/root/chroot_tmpdir/scmroot/ghc-base16-bytestring
Cloning into '/var/lib/mock/f39-build-1507021-35220/root/chroot_tmpdir/scmroot/ghc-base16-bytestring'...
$ git fetch origin 90f4809d5f029138e188cc67d1911933ee8f6dff:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-base16-bytestring
 * [new ref]         90f4809d5f029138e188cc67d1911933ee8f6dff -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 90f4809 bump release