Errors while executing compiler are not caught correctly

[nandenjin]

How to reproduce

Use this loader without emsdk

Expected

An error will be thrown by utility.getDependencies().

emcc-loader/src/utility.ts

Lines 24 to 30 in 2a3c0ba

	const { stdout } = await execute(compiler, [
	...flags,
	'-MM',
	absPath,
	]).catch(err => {
	throw err.err;
	});

What happened

It doesn't throw anything and returns an empty array. As a result, utility.getLatestModifiedTime() throws an error:

ERROR in ./src/main.clist
Module build failed (from ../../emcc-loader/lib/index.js):
Error: paths must be non-empty.
    at getLatestModifiedTime (/Users/nandenjin/workspace/emcc-loader/lib/index.js:63:15)
    at Compiler.compile (/Users/nandenjin/workspace/emcc-loader/lib/index.js:230:42)
    at processTicksAndRejections (internal/process/task_queues.js:97:5)
    at async Compiler.process (/Users/nandenjin/workspace/emcc-loader/lib/index.js:203:30)
 @ ./src/index.ts 12:0-34 30:22-39

How to fix

utility.execute() is designed that it passes error as its return value instead of throwing it.

emcc-loader/src/utility.ts

Lines 98 to 118 in 2a3c0ba

	return new Promise<SuccessType>((resolve, reject) => {
	childProcess.execFile(
	childProcessExecutable,
	childProcessArguments,
	options || {},
	(err, stdout, stderr) => {
	if (err) {
	resolve({
	err,
	stdout,
	stderr,
	});
	} else {
	resolve({
	stdout,
	stderr,
	});
	}
	}
	);
	});

So, it may be fixed with detecting errors with return value instead of using .catch()