Hi. Yhc doesn't like being built twice: $ scons configure && scons build # scons install $ scons clean $ scons build ... Checking whether byte ordering is bigendian... (cached) no Checking size of char... (cached) no Checking size of short... (cached) no Checking size of int... (cached) no Checking size of long... (cached) no Checking size of long long... (cached) no Checking size of float... (cached) no Checking size of double... (cached) no Checking size of void*... (cached) no Failed to check types sizes/endianness. You do have a working C compiler don't you? If so then please contact the Yhc developers for help. I had a C compiler a second ago. It seems the scons caching has gone awry: $ rm .sconsign.dblite $ scons build ... builds as usual. Charles.