When compiling a program these are the following errors that appear... /usr/share/aclocal/libmcrypt.m4:17: warning: underquoted definition of AM_PATH_LIBMCRYPT run info '(automake)Extending aclocal' or see http://sources.redhat.com/automake/automake.html#Extending%20aclocal
Needs to be fixed upstream... Also, those are not errors but harmless warnings (see the link).
The point of these bugs was for someone to follw up with it upstream.
vapier fixed this some while ago and didn't put it into the ChangeLog.