I can confirm that Jesse's patch allows multiprocessing to compile on
Solaris 10.  Note, however, that there are other symbolic constants
defined which contain "SEM_VALUE_MAX", all with widely differing
underlying values:

    % find /usr/include -name '*.h' | xargs egrep SEM_VALUE_MAX
    /usr/include/sys/param.h:#define        _SEM_VALUE_MAX          INT_MAX
    /usr/include/sys/sysconfig.h:#define    _CONFIG_SEM_VALUE_MAX   21 
    /* max. value a semaphore may have */
    /usr/include/sys/unistd.h:#define       _SC_SEM_VALUE_MAX          
    37
    /usr/include/limits.h:#define   _POSIX_SEM_VALUE_MAX    32767

How do we know that _SEM_VALUE_MAX is the proper rvalue to use when
#define-ing SEM_VALUE_MAX?

Richard, as the author of the original processing module do you have
something to contribute to this discussion?  You've been completely
silent on this issue.