In COMPILING.txt it says

Pioneer is known to build on the following platforms and build systems:
Linux: CMake with GCC 4.9+ or Clang 6+

The commit eada00c uses std::reduce, which comes from c++17. This raises the required minimal compiler version.

With g++ 7 cmake adds flag -std=gnu++1z, but the std::reduce is available since g++ 9.