olpcflash build failed

[Mitch Bradley]

My linuxbios builds started failing today (althought I haven't tried to 
build for over a week). olpcflash/logs/build.log says:

gcc -nostdinc -fpic -m32 -Os -march=i586 -isystem 
/home/wmb/OLPC/bios/staging/include -isystem 
/usr/lib/gcc/i486-linux-gnu/3.4.6//include -Wall -nostdlib 
-L/home/wmb/OLPC/bios/staging/lib 
-Wl,-rpath-link,/home/wmb/OLPC/bios/staging/lib 
-Wl,--dynamic-linker,/lib/ld-uClibc.so.0  -o olpcflash olpcflash.c 
/home/wmb/OLPC/bios/staging/lib/crt1.o -lc 
/usr/lib/gcc/i486-linux-gnu/3.4.6/libgcc.a
olpcflash.c:34:19: errno.h: No such file or directory
olpcflash.c:35:19: fcntl.h: No such file or directory
... (many other garden variety include files missing) ...
olpcflash.c:99: error: `NULL' undeclared here (not in a function)
(etc)

I also tried on a gcc 4.1 installation and got essentially the same result.

The missing include files are indeed not present in 
/usr/lib/gcc/i486-linux-gnu/3.4.6/include

I'm sure I can figure this out myself given enough time, but perhaps 
someone happens to know what I need to install?

(The messages above are from debian unstable; the similar 4.1 result was 
under FC5)