Compiling the C compiler identification source file "CMakeCCompilerId.c" failed.
Compiler: /usr/bin/mpicc 
Build flags: -pipe;-march=native;-fno-diagnostics-color;-O2
Id flags:  

The output was:
1
/usr/lib/gcc/x86_64-pc-linux-gnu/11.2.0/../../../../x86_64-pc-linux-gnu/bin/ld: /usr/lib64/libmpi.so: undefined reference to `MPIR_being_debugged'
/usr/lib/gcc/x86_64-pc-linux-gnu/11.2.0/../../../../x86_64-pc-linux-gnu/bin/ld: /usr/lib64/libmpi.so: undefined reference to `orte_data_server_uri'
collect2: error: ld returned 1 exit status


Determining if files io.h exist failed with the following output:
Change Dir: /var/tmp/portage/sci-chemistry/gromacs-2021.2/work/gromacs-2021.2_float_mpi/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/ninja cmTC_2821e && [1/2] Building C object CMakeFiles/cmTC_2821e.dir/HAVE_IO_H.c.o
FAILED: CMakeFiles/cmTC_2821e.dir/HAVE_IO_H.c.o 
/usr/bin/mpicc    -pipe -march=native -fno-diagnostics-color -O2 -o CMakeFiles/cmTC_2821e.dir/HAVE_IO_H.c.o -c /var/tmp/portage/sci-chemistry/gromacs-2021.2/work/gromacs-2021.2_float_mpi/CMakeFiles/CheckIncludeFiles/HAVE_IO_H.c
/var/tmp/portage/sci-chemistry/gromacs-2021.2/work/gromacs-2021.2_float_mpi/CMakeFiles/CheckIncludeFiles/HAVE_IO_H.c:2:10: fatal error: io.h: No such file or directory
    2 | #include <io.h>
      |          ^~~~~~
compilation terminated.
ninja: build stopped: subcommand failed.


Source:
/* */
#include <io.h>


int main(void){return 0;}

Determining if the _fileno exist failed with the following output:
Change Dir: /var/tmp/portage/sci-chemistry/gromacs-2021.2/work/gromacs-2021.2_float_mpi/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/ninja cmTC_095dd && [1/2] Building CXX object CMakeFiles/cmTC_095dd.dir/CheckSymbolExists.cxx.o
FAILED: CMakeFiles/cmTC_095dd.dir/CheckSymbolExists.cxx.o 
/usr/bin/x86_64-pc-linux-gnu-g++    -pipe -march=native -fno-diagnostics-color -O2  -std=c++17 -o CMakeFiles/cmTC_095dd.dir/CheckSymbolExists.cxx.o -c /var/tmp/portage/sci-chemistry/gromacs-2021.2/work/gromacs-2021.2_float_mpi/CMakeFiles/CMakeTmp/CheckSymbolExists.cxx
/var/tmp/portage/sci-chemistry/gromacs-2021.2/work/gromacs-2021.2_float_mpi/CMakeFiles/CMakeTmp/CheckSymbolExists.cxx: In function ‘int main(int, char**)’:
/var/tmp/portage/sci-chemistry/gromacs-2021.2/work/gromacs-2021.2_float_mpi/CMakeFiles/CMakeTmp/CheckSymbolExists.cxx:8:19: error: ‘_fileno’ was not declared in this scope; did you mean ‘fileno’?
    8 |   return ((int*)(&_fileno))[argc];
      |                   ^~~~~~~
      |                   fileno
ninja: build stopped: subcommand failed.


File /var/tmp/portage/sci-chemistry/gromacs-2021.2/work/gromacs-2021.2_float_mpi/CMakeFiles/CMakeTmp/CheckSymbolExists.cxx:
/* */
#include <stdio.h>

int main(int argc, char** argv)
{
  (void)argv;
#ifndef _fileno
  return ((int*)(&_fileno))[argc];
#else
  (void)argc;
  return 0;
#endif
}
Determining if the _commit exist failed with the following output:
Change Dir: /var/tmp/portage/sci-chemistry/gromacs-2021.2/work/gromacs-2021.2_float_mpi/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/ninja cmTC_536f0 && [1/2] Building CXX object CMakeFiles/cmTC_536f0.dir/CheckSymbolExists.cxx.o
FAILED: CMakeFiles/cmTC_536f0.dir/CheckSymbolExists.cxx.o 
/usr/bin/x86_64-pc-linux-gnu-g++    -pipe -march=native -fno-diagnostics-color -O2  -std=c++17 -o CMakeFiles/cmTC_536f0.dir/CheckSymbolExists.cxx.o -c /var/tmp/portage/sci-chemistry/gromacs-2021.2/work/gromacs-2021.2_float_mpi/CMakeFiles/CMakeTmp/CheckSymbolExists.cxx
/var/tmp/portage/sci-chemistry/gromacs-2021.2/work/gromacs-2021.2_float_mpi/CMakeFiles/CMakeTmp/CheckSymbolExists.cxx:2:10: fatal error: io.h: No such file or directory
    2 | #include <io.h>
      |          ^~~~~~
compilation terminated.
ninja: build stopped: subcommand failed.


File /var/tmp/portage/sci-chemistry/gromacs-2021.2/work/gromacs-2021.2_float_mpi/CMakeFiles/CMakeTmp/CheckSymbolExists.cxx:
/* */
#include <io.h>

int main(int argc, char** argv)
{
  (void)argv;
#ifndef _commit
  return ((int*)(&_commit))[argc];
#else
  (void)argc;
  return 0;
#endif
}
Determining if the memalign exist failed with the following output:
Change Dir: /var/tmp/portage/sci-chemistry/gromacs-2021.2/work/gromacs-2021.2_float_mpi/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/ninja cmTC_f252e && [1/2] Building CXX object CMakeFiles/cmTC_f252e.dir/CheckSymbolExists.cxx.o
FAILED: CMakeFiles/cmTC_f252e.dir/CheckSymbolExists.cxx.o 
/usr/bin/x86_64-pc-linux-gnu-g++    -pipe -march=native -fno-diagnostics-color -O2  -std=c++17 -o CMakeFiles/cmTC_f252e.dir/CheckSymbolExists.cxx.o -c /var/tmp/portage/sci-chemistry/gromacs-2021.2/work/gromacs-2021.2_float_mpi/CMakeFiles/CMakeTmp/CheckSymbolExists.cxx
/var/tmp/portage/sci-chemistry/gromacs-2021.2/work/gromacs-2021.2_float_mpi/CMakeFiles/CMakeTmp/CheckSymbolExists.cxx: In function ‘int main(int, char**)’:
/var/tmp/portage/sci-chemistry/gromacs-2021.2/work/gromacs-2021.2_float_mpi/CMakeFiles/CMakeTmp/CheckSymbolExists.cxx:8:19: error: ‘memalign’ was not declared in this scope
    8 |   return ((int*)(&memalign))[argc];
      |                   ^~~~~~~~
ninja: build stopped: subcommand failed.


File /var/tmp/portage/sci-chemistry/gromacs-2021.2/work/gromacs-2021.2_float_mpi/CMakeFiles/CMakeTmp/CheckSymbolExists.cxx:
/* */
#include <stdlib.h>

int main(int argc, char** argv)
{
  (void)argv;
#ifndef memalign
  return ((int*)(&memalign))[argc];
#else
  (void)argc;
  return 0;
#endif
}
The MPI test test_mpi for C in mode normal failed to compile with the following output:
Change Dir: /var/tmp/portage/sci-chemistry/gromacs-2021.2/work/gromacs-2021.2_float_mpi/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/ninja cmTC_92f4d && [1/2] Building C object CMakeFiles/cmTC_92f4d.dir/test_mpi.c.o
[2/2] Linking C executable cmTC_92f4d
FAILED: cmTC_92f4d 
: && /usr/bin/mpicc -pipe -march=native -fno-diagnostics-color -O2 -Wl,-O1 -Wl,--as-needed -Wl,--defsym=__gentoo_check_ldflags__=0    -Wl,-rpath -Wl,/usr/lib64 -Wl,-rpath -Wl,/usr/lib64 -Wl,--enable-new-dtags -pthread CMakeFiles/cmTC_92f4d.dir/test_mpi.c.o -o cmTC_92f4d  /usr/lib64/libmpi.so && :
/usr/lib/gcc/x86_64-pc-linux-gnu/11.2.0/../../../../x86_64-pc-linux-gnu/bin/ld: /usr/lib64/libmpi.so: undefined reference to `MPIR_being_debugged'
/usr/lib/gcc/x86_64-pc-linux-gnu/11.2.0/../../../../x86_64-pc-linux-gnu/bin/ld: /usr/lib64/libmpi.so: undefined reference to `orte_data_server_uri'
collect2: error: ld returned 1 exit status
ninja: build stopped: subcommand failed.