People who brag about how cool and modern they are to require a C89 compiler (that’s you Python 2.6) should not be using // for comments. Maybe they meant they require a C99 compiler.
And yes, this really matters. On AIX 6.1 the Python 2.6 configure script selects a C89 compiler («cc_r -qlanglvl=extc89» if you must know). Which barfs on their warthog creating code.
Meh. Maybe I’ll even file a bug report.