Change `unwrap()`s to `expect()`s in `module.rs`

[ojeda]

Although we don't get output unless we use -Z proc-macro-backtrace, it is a good idea to provide some more details like we do for some of the others, e.g. in:

fn expect_punct(it: &mut token_stream::IntoIter) -> char {
    if let TokenTree::Punct(punct) = it.next().unwrap() {
    ...

This unwrap() may fail if we find the end of the stream unexpectedly (because the user didn't pass the arguments that we expected).

[Sylfrena]

Hullo,
Can I work on this issue?

[ojeda]

Of course!

[Sylfrena]

@ojeda Hi, this is something that should be obvious to me, but i am not really sure how to compile the changes I make. Rustc gives me these errors (which are not related to the changes I made). And using
make CC=clang M=rust is not really catching errors (I tried introducing some).
Running make for the entire kernel is sort of time taking, but is that the only way, or I am I missing something here?

[ojeda]

No worries! In general, the mailing list is best for things like this.

Running make for the entire kernel is sort of time taking, but is that the only way, or I am I missing something here?

Running make CC=clang for the entire kernel should only recompile what is needed -- even with a single core it should be very quick (handful of seconds) to reach the point where it compiles the Rust code if everything else is already compiled. Are you perhaps cleaning the build every time? Avoid using M=, it shouldn't be needed for your use case.