While running current devel on the at package, the test never completes. To reproduce - yumdownloader --source at - try-fedora-review -rn at-3.1.13-13.fc20.src.rpm
The problem seems to be that the grep command is invoked without argument, excerpt from log:
{{{ running: grep -E -n -o /y/at/BUILD/at-3.1.13/configure.ac }}}
Patch with as easy fix as possible. 0001-autotools-don-t-check-for-autoconf-yet.patch
Patch committed: 4c993c1309819ad5b213. Thanks for fix!