Failing Coverage on Xcode 26 (RC1): SwiftDemangleTests

[tinder-cwybranowski]

Issues

Hello, I'm observing 2 related issues in this repository involving the @com_github_lyft_swift_index_store//:SwiftDemangle target on Xcode 26 (RC1).

Any help would be greatly appreciated -- thanks!

Issue 1: Direct bazelisk coverage Failures

When I check out the latest commit of this repository, and run the following command:

bazelisk coverage //Tests/SwiftDemangleTests:SwiftDemangleTests

I observe the following failure (abbreviated to the relevant portion):

Test Suite 'All tests' passed at 2025-09-10 01:27:15.044.
         Executed 4 tests, with 0 failures (0 unexpected) in 0.001 (0.003) seconds
error: while exporting coverage report
error: failed to load coverage: '%executable%': No such file or directory
error: could not load coverage information
--
Coverage runner: Not collecting coverage for failed test.
The following commands failed with status 1

Issue 2: Transitive bazelisk coverage Failures

In another repository I work on, we depend on @com_github_lyft_swift_index_store//:SwiftDemangle in some of our swift_library targets. Any swift_library targets that depend on that target, either directly or transitively, also fail to invoke bazelisk coverage ... successfully -- terminating with something like the following:

Test Suite 'All tests' passed at 2025-09-09 23:53:37.295.
         Executed 1 test, with 0 failures (0 unexpected) in 0.000 (0.001) seconds
error: while exporting coverage report
error: failed to load coverage: 'ExampleUnitTests.xctest/Contents/MacOS/ExampleUnitTests': truncated coverage data
error: could not load coverage information

Notes

• bazelisk test //Tests/SwiftDemangleTests:SwiftDemangleTests works as expected (makes sense since the failure is related to coverage processing, not the test execution itself)
• bazelisk coverage //Tests/SwiftDemangleTests:SwiftDemangleTests and bazelisk coverage ... on our internal test targets works successfully on Xcode 16.2