Fix the `test-coverage` target

[shimkiv]

Preliminary Checks

• [X] This issue is not a duplicate. Before opening a new issue, please search existing issues: https://github.com/MinaProtocol/mina/issues
• [X] This issue is not a question, feature request, RFC, or anything other than a bug report. Please post those things in GitHub Discussions: https://github.com/MinaProtocol/mina/discussions

Description

Running the make test-coverage might fail some tests and ./src/lib/child_processes/tester.sh spawned process won't exit, it will remain running after the Make target completion.

But even though everything seems to be completed (including mentioned tester.sh process termination), some process continues creating the .coverage files within the Mina repo, at paths like:

src/lib/child_processes/bisect255697030.coverage
src/lib/integration_test_lib/bisect948728918.coverage

With the help of sudo fs_usage | grep coverage I found the following:

10:49:48  open              ./bisect787555795.coverage                                                       0.000087   ppx.exe
10:49:48    WrData[A]       ./bisect787555795.coverage                                                       0.000122 W ppx.exe

But no idea who spawns that ppx.exe process periodically to write new coverage data. The workaround for now could be in completely removing the _build directory.

Some logs: untitled.txt

Steps to Reproduce

Described in Description.

Expected Result

Described in Description.

Actual Result

Described in Description.

How frequently do you see this issue?

Always

What is the impact of this issue on your ability to run a node?

Low

Status

No need.

Additional information

No response