Error compiling HCC: <Mutex> not found

[saitam757]

Hi. I'm trying to compile Hcc on Solus Linux (Package files here ). Shortly before end of compiling I get the following error:

[90%] Built target hc_lib Scanning dependencies of target mcwamp_atomic
[ 90%] Generating workitem.
[ 90%] Building CXX object lib/CMakeFiles/mcwamp_atomic.dir/mcwamp_atomic.cpp.
/home/xxxx/Projekte/native_repro/hcc_git/hcc/lib/mcwamp_atomic.cpp:1:10: fatal error: 'mutex' file not found
#include <mutex>
^~~~~~~
1 error generated.

make[2]: *** [lib/CMakeFiles/mcwamp_atomic.dir/build.make:63: lib/CMakeFiles/mcwamp_atomic.dir/mcwamp_atomic.cpp.o] Fehler 1
make[1]: *** [CMakeFiles/Makefile2:151437: lib/CMakeFiles/mcwamp_atomic.dir/all] Fehler 2

Mutex I would guess something with pthreads but thats installed. GCC compiler is 8.3.1. Does anybody has an idea what causes the error ? Thank you.