“if you are into pain, get the autotools book.. Read it awhile, throw it in a box and start sacrificing to Cthulu.”
From the courier FAQ:
Q: The configure script is stuck in an infinite loop A: It's not. The Courier mail server is made up of over thirty modular pieces, and each one has its own configure script. All configure scripts are recursively executed. configure scripts are generated off a template, and share a lot of common code, so when configure runs, it seems like the same script is being executed over and over again.