$ git clone -n https://src.fedoraproject.org/rpms/libblockdev.git /var/lib/mock/f39-build-1549115-36887/root/chroot_tmpdir/scmroot/libblockdev
Cloning into '/var/lib/mock/f39-build-1549115-36887/root/chroot_tmpdir/scmroot/libblockdev'...
$ git fetch origin c25c1e9f4467d21897951b729fda474692c9a107:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libblockdev
 * [new ref]         c25c1e9f4467d21897951b729fda474692c9a107 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c25c1e9 New version 3.0.4