https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71856
--- Comment #2 from Michael Hamann <michael.hamann at kit dot edu> --- This is not about activating parallel mode, this is about using individual parallel algorithms by directly including e.g. <parallel/algorithm> and using the namespace __gnu_parallel explicitly. There I do not get the error you mention. Is this not supported, too?
