src/vs/base/node/processes.ts/LineProcess/handleSpawn
class LineProcess:	protected handleSpawn(childProcess: cp.ChildProcess, cc: ValueCallback<SuccessData>, pp: ProgressCallback<LineData>, ee: ErrorCallback, sync: boolean): void {
		const stdoutLineDecoder = new LineDecoder();
		const stderrLineDecoder = new LineDecoder();
		childProcess.stdout!.on('data', (data: Buffer) => {
			const lines = stdoutLineDecoder.write(data);
			lines.forEach(line => pp({ line: line, source: Source.stdout }));
		});
		childProcess.stderr!.on('data', (data: Buffer) => {
			const lines = stderrLineDecoder.write(data);
			lines.forEach(line => pp({ line: line, source: Source.stderr }));
		});

		this.stdoutLineDecoder = stdoutLineDecoder;
		this.stderrLineDecoder = stderrLineDecoder;
	}