I'm getting the following warning from aclocal 1.9.5 with libmcrypt 2.5.7: /usr/share/aclocal/libmcrypt.m4:17: warning: underquoted definition of AM_PATH_LIBMCRYPT
Created attachment 58576 [details, diff] patch fixes the warning
The patch is already there - maybe you should emerge sync?
patch is already there from what I can see.