$ git clone -n https://src.fedoraproject.org/rpms/openjdk-asmtools.git /var/lib/mock/f40-build-1965565-25205/root/chroot_tmpdir/scmroot/openjdk-asmtools
Cloning into '/var/lib/mock/f40-build-1965565-25205/root/chroot_tmpdir/scmroot/openjdk-asmtools'...
$ git fetch origin 2693069fb6041c97ca75c765a72233359096c213:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/openjdk-asmtools
 * [new ref]         2693069fb6041c97ca75c765a72233359096c213 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2693069 experimental drop of java_home