The old joy of watching logs of a stupid GNU script checking basic features of the GNU C compiler. Just in case someone installed a compiler that had a different implementation.
I was referring to the tedious wait for the configure script. It might not seem so bad now, but what's a mild annoyance on modern computer with an SSD is quite the interruption on a few hundred MHz and spinning rust.
Another thing I wish it would do is give you all of the missing dependencies up front. Aain, not so bad now, but it was a major hassle for me when a missing dependency meant a long walk to the local library, 4gb flash drive in hand.
Especially lovely now when one might want to use clang and some CFLAG you set breaks a bad check. It's also very annoying to correctly pass PIC and PIE flags when the makefile builds both libraries and executables. I loathe automake.