Hi Freddie,

I have a similar problem.

I installed Anaconda distribution, therefore I am not sure about the compiler but mpi4py seems to work only with Intel MPI. At first it was installing using MS MPI with wrong directories, then I corrected them with correct MS MPI. But the result of famous mpiexec -4  hello.py was always 0. Then I tried with Intel MPI and it worked. I checked MS MPI and Intel MPI also with VS Intel Fortran and the result was the same.

However when I run Couette example with either of them, the result is:

INTEL MPI

Traceback (most recent call last):
  File "c:\users\pc\downloads\pyfr-1.3.0\pyfr-1.3.0\pyfr\util.py", line 32, in __call__
    res = cache[key]
KeyError: (<function OpenMPKernelProvider._build_kernel at 0x00000165AEBC0488>, b'\x80\x03X\n\x00\x00\x00negdivconfq\x00X^\r\x00\x00\n\n#include <omp.h>\n#include <stdlib.h>\n#include <tgmath.h>\n\n#define PYFR_ALIGN_BYTES 32\n#define PYFR_NOINLINE __attribute__ ((noinline))\n\n#define min(a, b) ((a) < (b) ? (a) : (b))\n#define max(a, b) ((a) > (b) ? (a) : (b))\n\n// Typedefs\ntypedef double fpdtype_t;\n\n// OpenMP static loop scheduling functions\n\nstatic inline int\ngcd(int a, int b)\n{\n    return (a == 0) ? b : gcd(b % a, a);\n}\n\nstatic inline void\nloop_sched_1d(int n, int align, int *b, int *e)\n{\n    int tid = omp_get_thread_num();\n    int nth = omp_get_num_threads();\n\n    // Round up n to be a multiple of nth\n    int rn = n + nth - 1 - (n - 1) % nth;\n\n    // Nominal tile size\n    int sz = rn / nth;\n\n    // Handle alignment\n    sz += align - 1 - (sz - 1) % align;\n\n    // Assign the starting and ending index\n    *b = sz * tid;\n    *e = min(*b + sz, n);\n\n    // Clamp\n    if (*b >= n)\n        *b = *e = 0;\n}\n\nstatic inline void\nloop_sched_2d(int nrow, int ncol, int colalign,\n              int *rowb, int *rowe, int *colb, int *cole)\n{\n    int tid = omp_get_thread_num();\n    int nth = omp_get_num_threads();\n\n    // Distribute threads\n    int nrowth = gcd(nrow, nth);\n    int ncolth = nth / nrowth;\n\n    // Row and column indices for our thread\n    int rowix = tid / ncolth;\n    int colix = tid % ncolth;\n\n    // Round up ncol to be a multiple of ncolth\n    int rncol = ncol + ncolth - 1 - (ncol - 1) % ncolth;\n\n    // Nominal tile size\n    int ntilerow = nrow / nrowth;\n    int ntilecol = rncol / ncolth;\n\n    // Handle column alignment\n    ntilecol += colalign - 1 - (ntilecol - 1) % colalign;\n\n    // Assign the starting and ending row to each thread\n    *rowb = ntilerow * rowix;\n    *rowe = *rowb + ntilerow;\n\n    // Assign the starting and ending column to each thread\n    *colb = ntilecol * colix;\n    *cole = min(*colb + ntilecol, ncol);\n\n    // Clamp\n    if (*colb >= ncol)\n        *colb = *cole = 0;\n}\n\n\n\n\n\nstatic PYFR_NOINLINE void negdivconf_inner(int _nx, const fpdtype_t *__restrict__ rcpdjac_v, fpdtype_t *__restrict__ tdivtconf_v0, fpdtype_t *__restrict__ tdivtconf_v1, fpdtype_t *__restrict__ tdivtconf_v2, fpdtype_t *__restrict__ tdivtconf_v3)\n               {\n                   for (int _x = 0; _x < _nx; _x++)\n                   {\n                       \n    tdivtconf_v0[_x] = -rcpdjac_v[_x]*tdivtconf_v0[_x] + (0.);\n    tdivtconf_v1[_x] = -rcpdjac_v[_x]*tdivtconf_v1[_x] + (0.);\n    tdivtconf_v2[_x] = -rcpdjac_v[_x]*tdivtconf_v2[_x] + (0.);\n    tdivtconf_v3[_x] = -rcpdjac_v[_x]*tdivtconf_v3[_x] + (0.);\n\n                   }\n               }\n                   void negdivconf(int _ny, int _nx, const fpdtype_t* __restrict__ rcpdjac_v, int lsdrcpdjac, fpdtype_t* __restrict__ tdivtconf_v, int lsdtdivtconf)\n                   {\n                       #pragma omp parallel\n                       {\n                           int align = PYFR_ALIGN_BYTES / sizeof(fpdtype_t);\n                           int rb, re, cb, ce;\n                           loop_sched_2d(_ny, _nx, align, &rb, &re, &cb, &ce);\n                           for (int _y = rb; _y < re; _y++)\n                           {\n                               negdivconf_inner(ce - cb, rcpdjac_v + _y*lsdrcpdjac + cb, tdivtconf_v + (_y*4 + 0)*lsdtdivtconf + cb, tdivtconf_v + (_y*4 + 1)*lsdtdivtconf + cb, tdivtconf_v + (_y*4 + 2)*lsdtdivtconf + cb, tdivtconf_v + (_y*4 + 3)*lsdtdivtconf + cb);\n                           }\n                       }\n                   }\n\nq\x01]q\x02(cnumpy\nint32\nq\x03h\x03cnumpy\nint64\nq\x04h\x03h\x04h\x03e\x87q\x05.', b'\x80\x03}q\x00.')

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Users\Pc\Anaconda3\lib\site-packages\pytools\prefork.py", line 46, in call_capture_output
    popen = Popen(cmdline, cwd=cwd, stdin=PIPE, stdout=PIPE, stderr=PIPE)
  File "C:\Users\Pc\Anaconda3\lib\subprocess.py", line 950, in __init__
    restore_signals, start_new_session)
  File "C:\Users\Pc\Anaconda3\lib\subprocess.py", line 1220, in _execute_child
    startupinfo)
FileNotFoundError: [WinError 2] Sistem belirtilen dosyayı bulamıyor

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Users\Pc\Anaconda3\Scripts\pyfr-script.py", line 9, in <module>
    load_entry_point('pyfr', 'console_scripts', 'pyfr')()
  File "c:\users\pc\downloads\pyfr-1.3.0\pyfr-1.3.0\pyfr\scripts\main.py", line 109, in main
    args.process(args)
  File "c:\users\pc\downloads\pyfr-1.3.0\pyfr-1.3.0\pyfr\scripts\main.py", line 230, in process_run
    args, NativeReader(args.mesh), None, Inifile.load(args.cfg)
  File "c:\users\pc\downloads\pyfr-1.3.0\pyfr-1.3.0\pyfr\scripts\main.py", line 214, in _process_common
    solver = get_solver(backend, rallocs, mesh, soln, cfg)
  File "c:\users\pc\downloads\pyfr-1.3.0\pyfr-1.3.0\pyfr\solvers\__init__.py", line 14, in get_solver
    return get_integrator(backend, systemcls, rallocs, mesh, initsoln, cfg)
  File "c:\users\pc\downloads\pyfr-1.3.0\pyfr-1.3.0\pyfr\integrators\__init__.py", line 26, in get_integrator
    return integrator(backend, systemcls, rallocs, mesh, initsoln, cfg)
  File "c:\users\pc\downloads\pyfr-1.3.0\pyfr-1.3.0\pyfr\integrators\controllers.py", line 14, in __init__
    super().__init__(*args, **kwargs)
  File "c:\users\pc\downloads\pyfr-1.3.0\pyfr-1.3.0\pyfr\integrators\steppers.py", line 9, in __init__
    super().__init__(*args, **kwargs)
  File "c:\users\pc\downloads\pyfr-1.3.0\pyfr-1.3.0\pyfr\integrators\base.py", line 41, in __init__
    self.system = systemcls(backend, rallocs, mesh, initsoln, nreg, cfg)
  File "c:\users\pc\downloads\pyfr-1.3.0\pyfr-1.3.0\pyfr\solvers\base\system.py", line 59, in __init__
    self._gen_kernels(eles, int_inters, mpi_inters, bc_inters)
  File "c:\users\pc\downloads\pyfr-1.3.0\pyfr-1.3.0\pyfr\solvers\base\system.py", line 167, in _gen_kernels
    kernels[pn, kn].append(kgetter())
  File "c:\users\pc\downloads\pyfr-1.3.0\pyfr-1.3.0\pyfr\solvers\baseadvec\elements.py", line 116, in <lambda>
    rcpdjac=self.rcpdjac_at('upts'), ploc=plocupts, u=solnupts
  File "c:\users\pc\downloads\pyfr-1.3.0\pyfr-1.3.0\pyfr\backends\base\backend.py", line 154, in kernel
    return kern(*args, **kwargs)
  File "c:\users\pc\downloads\pyfr-1.3.0\pyfr-1.3.0\pyfr\backends\base\kernels.py", line 162, in kernel_meth
    fun = self._build_kernel(name, src, list(it.chain(*argt)))
  File "c:\users\pc\downloads\pyfr-1.3.0\pyfr-1.3.0\pyfr\util.py", line 34, in __call__
    res = cache[key] = self.func(*args, **kwargs)
  File "c:\users\pc\downloads\pyfr-1.3.0\pyfr-1.3.0\pyfr\backends\openmp\provider.py", line 13, in _build_kernel
    mod = GccSourceModule(src, self.backend.cfg)
  File "c:\users\pc\downloads\pyfr-1.3.0\pyfr-1.3.0\pyfr\backends\openmp\compiler.py", line 61, in __init__
    super().__init__(src, cfg)
  File "c:\users\pc\downloads\pyfr-1.3.0\pyfr-1.3.0\pyfr\backends\openmp\compiler.py", line 30, in __init__
    lname = self._build(tmpdir)
  File "c:\users\pc\downloads\pyfr-1.3.0\pyfr-1.3.0\pyfr\backends\openmp\compiler.py", line 80, in _build
    call_capture_output(cmd + self._cflags, cwd=tmpdir)
  File "C:\Users\Pc\Anaconda3\lib\site-packages\pytools\prefork.py", line 197, in call_capture_output
    return forker[0].call_capture_output(cmdline, cwd, error_on_nonzero)
  File "C:\Users\Pc\Anaconda3\lib\site-packages\pytools\prefork.py", line 54, in call_capture_output
    % ( " ".join(cmdline), e))
pytools.prefork.ExecError: error invoking 'cc -shared -std=c99 -Ofast -march=native -fopenmp -fPIC -o libtmp.so tmp.c': [WinError 2] Cannot find defined file