setup.py: skip inotify if there's no inotify_add_watch Debian Etch doesn't include a sys/inotify.h header, which makes it impossible to compile _inotify.c, making hg uninstallable. The cc.has_function() method is implemented by trying to compile a simple C program. Since there's no redirection involved all error messages are sent to the terminal. This is not particularly pretty but at least it allows the installation to complete.