$ git clone -n https://src.fedoraproject.org/rpms/R-tesseract.git /var/lib/mock/f42-build-side-1-3583038-46887/root/chroot_tmpdir/scmroot/R-tesseract
Cloning into '/var/lib/mock/f42-build-side-1-3583038-46887/root/chroot_tmpdir/scmroot/R-tesseract'...
$ git fetch origin 021da957749443f7bd4221b8d3481ec6e5d1df2a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-tesseract
 * [new ref]         021da957749443f7bd4221b8d3481ec6e5d1df2a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 021da95 R-maint-sig mass rebuild