Broken sed cause build problems

Why sed

The configure script uses sed to amongst other things generate the root Makefile.

Bad sed

It has turned out that some versions of sed (in the 4.0.X series it seems) don't properly support \n within the replacement string for the 'c' command.

Good sed

sed 4.1.2 and later are known to do right. sed version 3 also works fine.