coverage-worker not working during fuzzing

[acsrlabs]

When using the --coverage-worker flag during cargo ziggy fuzz, ziggy crashes on trying to generate coverage.

error: no input files specified. See llvm-profdata merge -help

thread '<unnamed>' (1847611) panicked at /home/ac/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/ziggy-1.7.0/src/bin/cargo-ziggy/fuzz.rs:286:33:
called `Result::unwrap()` on an `Err` value: ⚠️  llvm-profdata failed with exit code `exit status: 1`
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

thread 'main' (1604685) panicked at /home/ac/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/ziggy-1.7.0/src/bin/cargo-ziggy/fuzz.rs:203:46:
called `Result::unwrap()` on an `Err` value: PoisonError { .. }

[louismerlin]

Fixed in #170, will publish a minor release today 😄

[louismerlin]

Woops nevermind it's another issue 🙃

[acsrlabs]

I think it's probably somehow related to the other issue. I added some more info. I would love to take a shot at fixing this, if that would be alright.

[louismerlin]

Of course!

[chris-srlabs]

An integration test for the coverage worker with tweaked --coverage-interval and --corpus-sync-interval (to avoid long running tests; maybe even 0 works for them) would be nice.