Building x64 cross-compiler, can't find gcc

While attempting to build a Rust cross-compiler in x64 Ubuntu with a target of sparcv9-sun-solaris, I get this:

michele@michele-VirtualBox:~/rust$ ./x.py build --target sparcv9-sun-solaris
Updating only changed submodules
Submodules updated in 0.07 seconds
    Finished dev [unoptimized] target(s) in 0.17s
thread 'main' panicked at '

couldn't find required command: "sparcv9-sun-solaris-gcc"

', src/bootstrap/sanity.rs:58:13
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace.
failed to run: /home/michele/rust/build/bootstrap/debug/bootstrap build --target sparcv9-sun-solaris
Build completed unsuccessfully in 0:00:00
michele@michele-VirtualBox:~/rust$ 

The gcc cross-compiler it's looking for is here (but with a different name):

michele@michele-VirtualBox:/usr/sparcv9-solaris/solaris/cross/bin$ ls -l sparcv9-solaris2.11-gcc
-rwxr-xr-x 2 root root 5269840 Feb 24 19:34 sparcv9-solaris2.11-gcc

How do I inform x.py of this fact? I've tried adding cross/bin to my PATH and doing an ln -s. Didn't work.

You can set these in a [target.sparcv9-sun-solaris] section in your config.toml.

So something like cc=" /usr/sparcv9-solaris/solaris/cross/bin/sparcv9-solaris2.11-gcc" ?

UPDATE: Yup, that did it. Also had to add a line for c++ too. It's now compiling away. Thanks.