rustdoc --version fails

[brson]

brian@brian-X1:~/dev/rust4/build$ x86_64-unknown-linux-gnu/stage2/bin/rustdoc --version
task '

' failed at 'called Result::unwrap() on an Err value', /home/brian/dev/rust4/src/libstd/result.rs:189

[eastwood]

I believe I think this is just for any argument, 'rustdoc -t' for example throws same error.
I don't think there is an implemented argument for version or default case

pub fn opts() -> ~[groups::OptGroup] {
    use extra::getopts::groups::*;
    ~[
        optflag("h", "help", "show this help message"),
        optopt("r", "input-format", "the input type of the specified file",
               "[rust|json]"),
        optopt("w", "output-format", "the output type to write",
               "[html|json]"),
        optopt("o", "output", "where to place the output", "PATH"),
        optmulti("L", "library-path", "directory to add to crate search path",
                 "DIR"),
        optmulti("", "cfg", "pass a --cfg to rustc", ""),
        optmulti("", "plugin-path", "directory to load plugins from", "DIR"),
        optmulti("", "passes", "space separated list of passes to also run, a \
                                value of `list` will print available passes",
                 "PASSES"),
        optmulti("", "plugins", "space separated list of plugins to also load",
                 "PLUGINS"),
        optflag("", "no-defaults", "don't run the default passes"),
        optflag("", "test", "run code examples as tests"),
        optmulti("", "test-args", "arguments to pass to the test runner",
                 "ARGS"),
    ]
}

[alexcrichton]

Reopening, the actual bug here is that it should support the --version flag.