$ git clone -n https://src.fedoraproject.org/rpms/java-latest-openjdk-portable.git /var/lib/mock/f39-build-1995457-43802/root/chroot_tmpdir/scmroot/java-latest-openjdk-portable
Cloning into '/var/lib/mock/f39-build-1995457-43802/root/chroot_tmpdir/scmroot/java-latest-openjdk-portable'...
$ git fetch origin 0066a17fe1b16dab26edc793cd2a65c5e6fdf2d8:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/java-latest-openjdk-portable
 * [new ref]         0066a17fe1b16dab26edc793cd2a65c5e6fdf2d8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 0066a17 cosmetic changes