🚀 go-pugleaf

A fwe times people have reported that GNU C++ will compile their
files, and make it to the link stage, only to have _main undefined.  I
now know the cause for this problem: bison is out of date.  At least
one old version of bison would return an error status (silently) when
it encountered a syntax error.  GNU C++ does not check the return
status of yyparse, instead it relies on the parser to detect and
record all relavent errors.  Since the error is not recorded, GNU C++
assumes that evrything is ok, and hence does not return an error
status.  The result is partially compiled programs.

Getting the latest version of bison fixes this problem.

Michael