-doc-search-tag="asyncprocimpl: proc runGetOutput(sh: ProcArgs; cmd: seq[string]; prefixCmd = none(seq[string]);
             toAdd: set[ProcOption] = {}; toRemove: set[ProcOption] = {};
             input = none(AsyncIoBase); output = none(AsyncIoBase);
             outputErr = none(AsyncIoBase); env = none(ProcEnv);
             envModifier = none(ProcEnv); workingDir = none(string);
             processName = none(string); logFn = none(LogFn);
             onErrorFn = none(OnErrorFn); cancelFut: Future[v