Miscellany

checking if /usr/bin/m4 has the division involving negative numbers bug... yes
configure: error: It appears that /usr/bin/m4 has a bug involving division
with negative numbers.  In particular it just returned the result that
-2/2 = 2147483647 instead of -1.  This is a known bug in GNU m4-1.4.9.  Please
install a non-broken m4.