[jpstewart]

IRIX ld is very picky about the order in which libraries are listed.  It scans them in the order they are named on the command line and uses them to resolve any unresolved symbols from prior objects.  It doesn't carry them forward, so to speak, to subsequent objects.  (Unlike, say, GNU ld which doesn't care about order at all.)

So, to me, the glaring mistake is that your hello.o object is listed last.  None of the libraries in your command will be used to resolve symbols in hello.o.  But hello.o will be used to resolve symbols in them (of which there should be none).  So that's backwards.  Put hello.o before all the libraries so that they can be used to satisfy the symbols in hello.o.