$ git clone -n https://src.fedoraproject.org/rpms/flang.git /var/lib/mock/f39-build-2368486-60389/root/chroot_tmpdir/scmroot/flang
Cloning into '/var/lib/mock/f39-build-2368486-60389/root/chroot_tmpdir/scmroot/flang'...
$ git fetch origin cb471028148da6da2bf354252c864fca8c595b12:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/flang
 * [new ref]         cb471028148da6da2bf354252c864fca8c595b12 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
warning: unable to unlink '/var/lib/mock/f39-build-2368486-60389/root/chroot_tmpdir/scmroot/flang/.git/refs/heads/rawhide.lock': Read-only file system
warning: unable to unlink '/var/lib/mock/f39-build-2368486-60389/root/chroot_tmpdir/scmroot/flang/.git/HEAD.lock': Read-only file system
error: update_ref failed for ref 'HEAD': couldn't set 'refs/heads/rawhide'
$ git reset --hard cb471028148da6da2bf354252c864fca8c595b12
fatal: Unable to create '/var/lib/mock/f39-build-2368486-60389/root/chroot_tmpdir/scmroot/flang/.git/index.lock': Read-only file system