If someone were to develop a tool that compared consecutive
./configure runs and reported major differences, that'd be cool.
I don't know how difficult that'd be though. I suspect if it
were easy someone might have done it by now, but who knows. ;o)
The log files might help with some of this. E.g. looking at changes
between different archs or if updating glibc could sometimes help.
greetings,
Florian La Roche