FoundCrate::Itself reported in doc tests

[h33p]

Hey there, it appears that FoundCrate::Itself is being returned when inside documentation tests. I currently work this around with the following snippet:

pub fn crate_path() -> TokenStream {
    let found_crate = crate_name("cglue").expect("cglue found in `Cargo.toml`");

    match found_crate {
        FoundCrate::Itself => {
            let has_doc_env = std::env::vars().any(|(k, _)| {
                k == "UNSTABLE_RUSTDOC_TEST_LINE" || k == "UNSTABLE_RUSTDOC_TEST_PATH"
            });

            if has_doc_env {
                quote!(::cglue)
            } else {
                quote!(crate)
            }
        }
        FoundCrate::Name(name) => quote!(::#name),
    }
}

Now, these environment variables are clearly not stable, but it was the only way I could distinguish doc tests, sooooo I don't know, the worst that could happen is these variables being removed.

[bkchr]

Hey,
sadly there isn't anything I can do here. There is nothing to detect if this is a doc test or not.

The best is to do the following:

extern crate self as cglue;

[CobaltCause]

You could use your own environment variable, for example DOCTEST_MODE, and then run your CI like this:

cargo test --tests # everything except doctests
DOCTEST_MODE="" cargo test --doc # only doctests

Since #13, you could also just use proc-macro-crate as normal, and use the above snippet in CI except with the CARGO_TARGET_TMPDIR environment variable.

[jplatte]

Hey, sadly there isn't anything I can do here. There is nothing to detect if this is a doc test or not.

The best is to do the following:

extern crate self as cglue;

But that only works if ones emits the crate name on FoundCrate::Itself, which defeats the purpose of that enum variant. I feel like this should be re-opened (with a blocked label potentially`) and only closed once it is possible (through Cargo / rustc changes) to make this work.

[bkchr]

I mean this entire crate is a hack around some missing feature in rustc :P I somehow still hope that rustc at some day brings "native" support for this.