$ git clone -n https://src.fedoraproject.org/rpms/libdwarf.git /var/lib/mock/eln-build-side-115451-61188930-6589425/root/chroot_tmpdir/scmroot/libdwarf
Cloning into '/var/lib/mock/eln-build-side-115451-61188930-6589425/root/chroot_tmpdir/scmroot/libdwarf'...
$ git fetch origin 40b79eb667ca6a12892625e07298195c52e3b5f2:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libdwarf
 * [new ref]         40b79eb667ca6a12892625e07298195c52e3b5f2 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 40b79eb Update sources