[profile.test.package."*"] is not used for tests

[Urcra]

Problem

When specifying overrides for cargo test to optimise tests in some workspace member on would expect to use

[profile.test.package.MEMBER]
opt-level = 2

[profile.test.package."*"]
opt-level = 2

But this won't actually apply the opt-level = 2 to the dependencies when invoking cargo test, instead if one needs dependencies to be optimized for the tests the following should be specified

[profile.test.package.MEMBER]
opt-level = 2

[profile.dev.package."*"]
opt-level = 2

Steps

1. Create some tests that requires dependencies to be optimized to run
2. Use Cargo.toml with [profile.test.package."*"]
3. Check that the tests are still not running due to non-optimized dependencies
4. Use Cargo.toml with [profile.dev.package."*"]
5. Verify that the tests are now running due to optimized dependencies

Possible Solution(s)

I'm guessing this happens since the dependencies used by cargo test is compiled with dev such that the same dependencies can be reused for debug builds and for testing, which seems fine.

Having a warning be triggered to note users that [profile.test.package."*"] doesn't do anything seems like a fair fix

Alternatively allowing [profile.test.package."*"] and applying it to test dependencies instead of [profile.dev.package."*"]

Notes

Output of cargo version: cargo 1.48.0 (65cbdd2 2020-10-14)

[ehuss]

This is expected behavior. The test profile only applies to the final test executable. This is described a little bit at https://doc.rust-lang.org/cargo/reference/profiles.html#profile-selection. I realize it may be a little confusing, but there are historical reasons why it works that way. We're looking to change that behavior as part of custom named profiles.

[ehuss]

I'm going to close this as it is expected behavior. You can subscribe to #6988 for further updates towards this issue.