$ git clone -n https://src.fedoraproject.org/rpms/vdr-screenshot.git /var/lib/mock/f42-build-864192-172199/root/chroot_tmpdir/scmroot/vdr-screenshot
Cloning into '/var/lib/mock/f42-build-864192-172199/root/chroot_tmpdir/scmroot/vdr-screenshot'...
$ git fetch origin cb15d5c474fa4626e86dc2028df7daea96107967:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/vdr-screenshot
 * [new ref]         cb15d5c474fa4626e86dc2028df7daea96107967 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at cb15d5c Rebuilt for new VDR API version 2.7.2