// run-pass UI test header does not work with extern crate

[phansch]

I'm trying to create a failing test for #3741 where I have to depend on an external proc-macro crate. The test itself looks like this:

// aux-build:proc_macro_crash.rs
// run-pass

#![feature(proc_macro_hygiene)]

extern crate proc_macro_crash;
use proc_macro_crash::macro_test;

fn main() {
    macro_test!(2);
}

In tests/ui/crashes/auxiliary/proc_macro_crash.rs I have:

// no-prefer-dynamic

#![feature(repr128)]
#![crate_type = "proc-macro"]

extern crate proc_macro;

use proc_macro::{Delimiter, Group, Ident, Span, TokenStream, TokenTree};
use std::iter::FromIterator;

#[proc_macro]
pub fn macro_test(input_stream: TokenStream) -> TokenStream {
    let first_token = input_stream.into_iter().next().unwrap();
    let span = first_token.span();

    TokenStream::from_iter(vec![
        TokenTree::Ident(Ident::new("fn", Span::call_site())),
        TokenTree::Ident(Ident::new("code", Span::call_site())),
        TokenTree::Group(Group::new(Delimiter::Parenthesis, TokenStream::new())),
        TokenTree::Group(Group::new(Delimiter::Brace, {
            let mut clause = Group::new(Delimiter::Brace, TokenStream::new());
            clause.set_span(span);

            TokenStream::from_iter(vec![
                TokenTree::Ident(Ident::new("if", Span::call_site())),
                TokenTree::Ident(Ident::new("true", Span::call_site())),
                TokenTree::Group(clause.clone()),
                TokenTree::Ident(Ident::new("else", Span::call_site())),
                TokenTree::Group(clause.clone()),
            ])
        })),
    ])
}

However, when I run the test using TESTNAME=ui/crashes/ice-3741 cargo uitest, I get the following error:

thread '[ui] ui/crashes/ice-3741.rs' panicked at 'failed to exec `"/home/phansch/code/rust-clippy/target/debug/test_build_base/crashes/ice-3741.stage-id"`: Os {
 code: 2, kind: NotFound, message: "No such file or directory" }', src/libcore/result.rs:997:5
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.                   
stack backtrace:                                     
   <snip unwind stuff>                                                  
   7: core::panicking::panic_fmt            
             at src/libcore/panicking.rs:85                                                    
   8: core::result::unwrap_failed                                        
             at /rustc/dec0a98c4b392b5fd153ba8b944c496218717813/src/libcore/macros.rs:18 
   9: core::result::Result<T,E>::expect
             at /rustc/dec0a98c4b392b5fd153ba8b944c496218717813/src/libcore/result.rs:825
  10: compiletest_rs::runtest::TestCx::compose_and_run
             at /home/phansch/.cargo/registry/src/github.com-1ecc6299db9ec823/compiletest_rs-0.3.19/src/runtest.rs:1359
  11: compiletest_rs::runtest::TestCx::exec_compiled_test                              
             at /home/phansch/.cargo/registry/src/github.com-1ecc6299db9ec823/compiletest_rs-0.3.19/src/runtest.rs:1228
  12: compiletest_rs::runtest::TestCx::run_ui_test
             at /home/phansch/.cargo/registry/src/github.com-1ecc6299db9ec823/compiletest_rs-0.3.19/src/runtest.rs:2312

The test passes without run-pass and also works when no extern crate is used, so maybe the auxiliary dependency is not passed through to the rustc command triggered by compiletest?

cc @oli-obk because you mentioned once on Discord that you think this can probably be fixed in Clippy?

[phansch]

I can confirm that it works in a default compiletest setup, so this probably not an issue in compiletest-rs but in Clippy.

[phansch]

Oh, I think this may be because the test doesn't even compile, because it's not meant to compile currently. If it's doesn't compile, using run-pass rightfully says that the compiled file could not be found.