New test output is harder to follow and dumps extra libTesting output

[finagolfin]

Here is what the native build system produces when running the tests for swift-argument-parser with the latest 6.4 snapshot toolchain:

> swift test --build-system native
--- snip build output---
Test Suite 'swift-argument-parserPackageTests.xctest' passed at 2026-06-05 15:06:28.945.
         Executed 564 tests, with 0 failures (0 unexpected) in 13.343 (13.379) seconds
Test Suite 'All tests' passed at 2026-06-05 15:06:28.945.
         Executed 564 tests, with 0 failures (0 unexpected) in 13.343 (13.388) seconds
◇ Test run started.
↳ Testing Library Version: 6.4 (2f6e102e6ff60cf)
↳ Target Platform: arm64-apple-macosx
✔ Test run with 0 tests in 0 suites passed after 0.001 seconds.

Not great that it unnecessarily tells me that libTesting was run with no output, but still much better than what swift-build produces:

> swift test
--- snip build output---
Test Suite 'ArgumentParserEndToEndTests.xctest' passed at 2026-06-05 15:08:07.398.
         Executed 263 tests, with 0 failures (0 unexpected) in 0.937 (0.947) seconds
Test Suite 'All tests' passed at 2026-06-05 15:08:07.398.
         Executed 263 tests, with 0 failures (0 unexpected) in 0.937 (0.956) seconds
◇ Test run started.
↳ Testing Library Version: 6.4 (2f6e102e6ff60cf)
↳ Target Platform: arm64-apple-macosx
✔ Test run with 0 tests in 0 suites passed after 0.001 seconds.
◇ Test run started.
↳ Testing Library Version: 6.4 (2f6e102e6ff60cf)
↳ Target Platform: arm64-apple-macosx
✔ Test run with 0 tests in 0 suites passed after 0.001 seconds.
◇ Test run started.
↳ Testing Library Version: 6.4 (2f6e102e6ff60cf)
↳ Target Platform: arm64-apple-macosx
✔ Test run with 0 tests in 0 suites passed after 0.001 seconds.
◇ Test run started.
↳ Testing Library Version: 6.4 (2f6e102e6ff60cf)
↳ Target Platform: arm64-apple-macosx
✔ Test run with 0 tests in 0 suites passed after 0.001 seconds.
◇ Test run started.
↳ Testing Library Version: 6.4 (2f6e102e6ff60cf)
↳ Target Platform: arm64-apple-macosx
✔ Test run with 0 tests in 0 suites passed after 0.001 seconds.
◇ Test run started.
↳ Testing Library Version: 6.4 (2f6e102e6ff60cf)
↳ Target Platform: arm64-apple-macosx
✔ Test run with 0 tests in 0 suites passed after 0.001 seconds.
◇ Test run started.
↳ Testing Library Version: 6.4 (2f6e102e6ff60cf)
↳ Target Platform: arm64-apple-macosx
✔ Test run with 0 tests in 0 suites passed after 0.001 seconds.

Note that the XCTest tests are split up by test target, so there is no full summation of all the tests run at the end anymore. Since ArgumentParser has no Testing tests, it spits out the same "0 tests" message for all the test targets, which is useless info.

@grynspan and @dschaefer2, has there been any thought put into cleaning this up?

[dschaefer2]

Lots. We really need a much better progress/reporting system in SwiftPM for builds and tests. If you've checked the console log for a SwiftPM test run, it's even worse, so we have a vested interest in addressing it. Just a matter of finding the time.

[grynspan]

The immediate problem is actually being fixed right about now with swiftlang/swift-package-manager#10166. Progress reporting etc. is something I think we'd love to build into the testing harness when we start on that (hopefully soon).

So I think we can transfer this to SwiftPM and then close it as completed?

[finagolfin]

Will that pull affect the above output which doesn't use --filter/--skip? If not, it won't help.

[grynspan]

For the moment, it is by design that we still emit output under those conditions. It's worth discussing internally though.