bug#18701: Intermittent build failures for man-pages

[Mark H Weaver]

There are intermittent build failures for man-pages.  See:

  http://hydra.gnu.org/job/gnu/master/man-pages-3.69.x86_64-linux
  http://hydra.gnu.org/job/gnu/master/man-pages-3.69.i686-linux

The failures are the same:

--8<---------------cut here---------------start------------->8---
starting phase `install'
for i in man?; do \
        install -d -m 755 
/gnu/store/9jfk1pgn4jrh3nzs2fmvihfyj7aglajq-man-pages-3.69/share/man/"$i" || 
exit $?; \
        install -m 644 "$i"/* 
/gnu/store/9jfk1pgn4jrh3nzs2fmvihfyj7aglajq-man-pages-3.69/share/man/"$i" || 
exit $?; \
done; \

install: cannot stat 'man6/*': No such file or directory
Makefile:53: recipe for target 'install' failed
make: *** [install] Error 1
--8<---------------cut here---------------end--------------->8---

       Mark