compiler_gym::util::LocalShellCommand::checkCall() does not kill process on timeout

[ChrisCummins]

🐛 Bug

If the process fails to terminate within the specified timeout period, it is abandoned:

CompilerGym/compiler_gym/util/Subprocess.cc

Lines 62 to 66 in 63dbfac

	if (!wait_for(process, timeout())) {
	return Status(StatusCode::DEADLINE_EXCEEDED,
	fmt::format("Command '{}' failed to complete within {} seconds", commandline(),
	timeoutSeconds()));
	}

Instead, the

To Reproduce

This unit test covers the timeout case:

CompilerGym/tests/util/SubprocessTest.cc

Lines 110 to 126 in 63dbfac

	TEST(Subprocess, checkCallTimeout) {
	Command proto;
	proto.add_argument("sleep");
	proto.add_argument("10");
	proto.set_timeout_seconds(1);
	LocalShellCommand cmd(proto);
	#ifdef __APPLE__
	// NOTE(github.com/facebookresearch/CompilerGym/issues/399): This test will
	// fail when the wait_for() problem is addressed.
	EXPECT_TRUE(cmd.checkCall().ok());
	#else // Linux
	const auto status = cmd.checkCall();
	EXPECT_EQ(status.error_code(), StatusCode::DEADLINE_EXCEEDED);
	EXPECT_EQ(status.error_message(), "Command 'sleep 10' failed to complete within 1 seconds");
	#endif
	}

run it using bazel test //tests/util:SubprocessTest.

Expected behavior

The child process should be terminated.

Environment

Please fill in this checklist:

• CompilerGym: 0.2.3
• How you installed CompilerGym (pip, source): source
• OS: Ubuntu 20.04
• Python version: 3.8
• Build command you used (if compiling from source): make install

Additional context

Reported by @uduse #326 (comment).