Just a short,terse list:
Don't use nondefault optimization. There is something going on
with the code that breaks, runtime, when compiled (which works
fine per se) with higher optimization levels. IPA is a real
difficulty.
Remember to set OBJECT_MODE=64 in OS env!
upgrading m4/autoconf and then configure seems to really help.
(m4 needs __STDC__ to get around "va_list" compilation error)
setting LIBPATH is quite helpful.