The build is very all-or-nothing in its code analysis. Feel free to suggest ways to make this incremental -- the code isn't compiled per-module like C-style languages.
The C API is not something you should target. Write pure Python instead of C extensions. If you're wrapping a C API, use Cython, which mostly stays within the boundaries of sanity (and might someday grow a ctypes target). Most of the C API (for certain values of "most") is only a recompile away.
Which obscure UNIX flavor did you need supported? The biggest obstacle to supporting other platforms is a lack of buildslaves and people well-versed in those platforms.
The C API is not something you should target. Write pure Python instead of C extensions. If you're wrapping a C API, use Cython, which mostly stays within the boundaries of sanity (and might someday grow a ctypes target). Most of the C API (for certain values of "most") is only a recompile away.
Which obscure UNIX flavor did you need supported? The biggest obstacle to supporting other platforms is a lack of buildslaves and people well-versed in those platforms.