cargo check --test foo compiles too much

[alexcrichton]

From a local compilation:

$ cargo new foo
$ cd foo
$ mkdir tests
$ touch tests/a.rs
$ cargo check --test a -v
   Compiling foo v0.1.0 (file:///home/alex/code/foo)
     Running `rustc --crate-name foo src/lib.rs --crate-type lib --emit=dep-info,link -C debuginfo=2 -C metadata=6d607d3e3579f789 -C extra-filename=-6d607d3e3579f789 --out-dir /home/alex/code/foo/target/debug/deps -L dependency=/home/alex/code/foo/target/debug/deps`
     Running `rustc --crate-name a tests/a.rs --emit=dep-info,link -C debuginfo=2 --test -C metadata=e8ff428dccc81b86 -C extra-filename=-e8ff428dccc81b86 --out-dir /home/alex/code/foo/target/debug/deps -L dependency=/home/alex/code/foo/target/debug/deps --extern foo=/home/alex/code/foo/target/debug/deps/libfoo-6d607d3e3579f789.rlib`
    Finished dev [unoptimized + debuginfo] target(s) in 0.32 secs

Notably nothing was compiled with metadata as an output.

cc @nrc

[tbourvon]

After investigating this issue, it seems that the problem comes from this line in cargo_compile.rs:

targets.append(&mut propose_indicated_targets(pkg, tests, "test", Target::is_test, test)?);

This line adds integration tests that match the --test X (or --tests) flag to the list of targets to be built. However, the profile passed to that function (the last argument) is the test profile, which has check == false. Hence code gets generated.

This could be fixed by passing the check_test profile from PR #4039 when we are checking, and test otherwise.

[tbourvon]

Should I take care of this issue in the same PR or should I open another one once the first is closed?

[alexcrichton]

@burningmind oh feel free to take care of this issue in your PR! No need for a separate one.

[ehuss]

This is fixed by #4592.