Source-based code coverage busted?

help
1

I'm trying to work through the code coverage example at GitHub - marco-c/rust-code-coverage-sample: Example of code coverage instrumentation in Rust. Everything "runs" fine, but when I examine the coverage report, it says 0% coverage.

I'm running an Intel Mac on OS 10.15.6, Rust 1.54.0 nightly (cargo 070e459c2 2021-05-11).

Is this a known issue?

Any suggested workarounds? Same happens in my own real project and is making dev work more difficult.

2

Never mind. Added this to my Makefile and all is well now:

test-with-coverage: rust-nightly
	rm -rf ./coverage/*.profraw
	RUSTFLAGS="-Z instrument-coverage" LLVM_PROFILE_FILE="./coverage/%p.profraw" cargo +nightly test
	# The LLVM_PROFILE_FILE trick is necessary; otherwise, the
	# .profraw files wind up in a last-writer-wins race which often
	# (always?) results in a report showing 0% coverage.