Allow creating test binaries with predictable names

[jjant]

Problem

I have a fleet of machines that build code, on these I want to run cargo build --tests to build a test binary, and hand that over to the machines that actually run the tests.

At the moment, because the generated binary has a non-predictable name (it contains a hash), we'd have to resort to the annoying trick of using --mesage-format=json and parse the output json to find the binary. See example.

Proposed Solution

It'd be nice to have a flag to name the test executable: cargo build --tests --out-name="my-tests-binary", or a way to remove the hash from the name.

Notes

No response

[weihanglo]

Thanks for the report!

It feels like Cargo targets generally have the same problem; only some of them are uplift to target/{debug,release}/ directory and have hash suffix erased. From my understanding, test/bench/example targets weren't designed to share final artifact outside the project.

There is an unstable feature different-binary-name (tracking issue #9778) enabling Cargo to set a different file name for [[bin]] targets. There are some discussions around mkaing it support [lib] target as well. Not sure if we want to extend its functionality to tests/benches/examples.

OTOH, here is a cargo rustc workaround. Could you try if it meets your need?

cargo rustc --test myinteg-test -- --emit link="myinteg-test.exe"

[ehuss]

I believe this is a duplicate of #3670.

[weihanglo]

Thanks for the info. Closing in favor of #3670.