Don't know, whether this is only cosmetical, but I saw this during emerge:
checking for ld used by i686-pc-linux-gnu-gcc... ./configure: line 3391: s%\\%/%g: No such file or directory
checking if the linker (/usr/i686-pc-linux-gnu/bin/ld) is GNU ld... (cached) yes
Reopen if you can reproduce it with 0.53.2 (and with confcache disable if you are using it).
fixed in 0.53
BTW I don't use confcache but for courier it should be worth to give it a try the configure step seems to need more time than the compile step.