Clearly *something* is going on here. Like John, I also haven't gotten
any multiple-def error messages, but:

53 zion> cat foo.c
int foo () { return 23423; }
54 zion> llvm-gcc -c -o foo.o foo.c
55 zion> llvm-ar foo.a foo.o
Member File Start: 8
Size: 124
Member File End: 192
56 zion> gccld -o=barf foo.a foo.a
gccld: Bytecode file 'foo.a' corrupt!: Invalid bytecode signature!
57 zion> gccld -o=barf -l=foo.a -l=foo.a
Not enough positional command line arguments specified!
Must specify at least 1 positional arguments: See: gccld --help
58 zion> gccld -o=barf -l=foo.a foo.a
gccld: Bytecode file 'foo.a' corrupt!: Invalid bytecode signature!

Maybe the strangeness of the UI should be a separate bug, though.
Leaving this as WFM.

For wierdness like this, see Bug 19