I'm using the academic version of EPD (Enthought Python Distribution) which is 32bit. My computer is Linux x86_64. platform.architecture() returns ('32bit','ELF') I want to install Mercurial. The instructions in README didn't work at first, because make gave this error: "LONG_BIT definition appears wrong for platform (bad gcc/glibc config?)." I commented out that line in pyport.h and then it compiled fine. Now, after successful compilation I get this error when running it: ImportError: /scratch/epd/lib/python2.6/site-packages/mercurial/osutil.so: wrong ELF class: ELFCLASS64 It appears that I compiled a 64bit version of hg, and it won't run with my 32bit python. I don't see any arch flags in the mercurial makefile. How can I force it to compile in 32bit mode?