I apparently have a file that simultaneously exists and does not exist:

/cross/src/gcc-4.6.1/gcc/../libcpp/include/line-map.h: No such file or directory
make[2]: *** [s-gtype] Error 1
make[2]: *** Waiting for unfinished jobs....
/bin/sh /cross/src/gcc-4.6.1/gcc/../move-if-change tmp-constants.h insn-constants.h
echo timestamp > s-enums
echo timestamp > s-constants
rm gfortran.pod gcc.pod
make[2]: Leaving directory `/cross/build/gcc-4.6.1/gcc'
make[1]: *** [all-gcc] Error 2
make[1]: Leaving directory `/cross/build/gcc-4.6.1'
make: *** [all] Error 2

Thomas@Khaos /cross/build/gcc-4.6.1
$ ls -l /cross/src/gcc-4.6.1/gcc/../libcpp/include/line-map.h
-rw-r--r-- 1 Thomas Administrators 7649 Jan  3  2011 /cross/src/gcc-4.6.1/gcc/../libcpp/include/line-map.h