Hi, On my home machine, I get the following errors with a fresh pull: Checking for GHC version 6.4.1 or later... Found version 6.4.2. Checking whether byte ordering is bigendian... conftest_0.c no Checking size of char... conftest_1.c 1 Checking size of short... conftest_2.c 2 Checking size of int... conftest_3.c 4 Checking size of long... conftest_4.c 4 Checking size of long long... failed Checking size of float... conftest_6.c 4 Checking size of double... conftest_7.c 8 Checking size of void*... conftest_8.c 4 Failed to check types sizes/endianness. You do have a working C compiler don't y ou? If so then please contact the Yhc developers for help. It seems to have passed almost all the tests, certainly has a working C compiler, but bottoms out. Is the long long test blowing it up? Thanks Neil