Windows Build fails

[traits]

🐛 Bug

For some days, I have a broken build on Windows (cf. appended error message)

To Reproduce

Steps to reproduce the behavior:

1. Pull master, submodules etc.
2. (Opt.) clear build directory
3. Build pytorch

Expected behavior

A finishing build

Environment

PyTorch version: N/A
Is debug build: N/A
CUDA used to build PyTorch: N/A

OS: Microsoft Windows 10 Pro
GCC version: Could not collect
CMake version: version 3.16.0

Python version: 3.7
Is CUDA available: N/A
CUDA runtime version: 10.2.89
GPU models and configuration: GPU 0: Quadro M1200
Nvidia driver version: 441.28
cuDNN version: C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v10.2\bin\cudnn64_7.dll

Versions of relevant libraries:
[pip3] msgpack-numpy==0.4.4.3

[pip3] numpy==1.17.4+mkl

[pip3] numpydoc==0.9.1

[pip3] torch==1.3.1 # I don't know, what this means - my pip call lists the same development version as conda

[pip3] torchvision==0.4.2
[conda] blas 1.0 mkl

[conda] libblas 3.8.0 14_mkl conda-forge

[conda] libcblas 3.8.0 14_mkl conda-forge

[conda] liblapack 3.8.0 14_mkl conda-forge

[conda] liblapacke 3.8.0 14_mkl conda-forge

[conda] mkl 2019.4 245

[conda] mkl-include 2019.4 245

[conda] mkl-service 2.3.0 py37hfa6e2cd_0 conda-forge

[conda] pytorch-sphinx-theme 0.0.24 dev_0

[conda] torch 1.4.0a0+6e145b4 pypi_0 pypi

[conda] torchvision 0.5.0a0+95131de pypi_0 pypi

Additional context

MS Visual Studio got an update lately - maybe the used C++ compiler is worth a check:

Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.24.28314\bin\Hostx64\x64\cl.exe

Error message from build:

[95/995] Building CXX object caffe2\CMakeFiles\torch_cpu.dir\core\blob_serialization.cc.obj                                                                                                               
FAILED: caffe2/CMakeFiles/torch_cpu.dir/core/blob_serialization.cc.obj                                                                                                                                    
C:\PROGRA~2\MICROS~2\2019\COMMUN~1\VC\Tools\MSVC\1424~1.283\bin\Hostx64\x64\cl.exe  /nologo /TP -DAT_PARALLEL_OPENMP=1 -DCPUINFO_SUPPORTED_PLATFORM=1 -DONNX_ML=1 -DONNX_NAMESPACE=onnx_torch -DTH_BLAS_MK
L -DWIN32_LEAN_AND_MEAN -D_CRT_SECURE_NO_DEPRECATE=1 -D_OPENMP_NOFORCE_MANIFEST -Dtorch_cpu_EXPORTS -Iaten\src -I..\aten\src -I. -I..\ -I..\cmake\..\third_party\benchmark\include -I..\third_party\onnx -
Ithird_party\onnx -I..\third_party\foxi -Ithird_party\foxi -I..\caffe2\..\torch\csrc\api -I..\caffe2\..\torch\csrc\api\include -I..\caffe2\aten\src\TH -Icaffe2\aten\src\TH -I..\caffe2\..\torch\..\aten\s
rc -Icaffe2\aten\src -Icaffe2\..\aten\src -Icaffe2\..\aten\src\ATen -I..\caffe2\..\torch\csrc -I..\caffe2\..\torch\..\third_party\miniz-2.0.8 -I..\aten\src\TH -I..\aten\..\third_party\catch\single_inclu
de -I..\aten\src\ATen\.. -Icaffe2\aten\src\ATen -I..\third_party\miniz-2.0.8 -I..\caffe2\core\nomnigraph\include -I..\c10\.. -I..\third_party\cpuinfo\include -I..\third_party\FP16\include -I..\cmake\..\
third_party\googletest\googlemock\include -I..\cmake\..\third_party\googletest\googletest\include -I..\third_party\protobuf\src -I"C:\Program Files (x86)\IntelSWTools\compilers_and_libraries\windows\mkl
\include" -IV:\bin\scripting\python\conda\envs\pytorch\Library\include -I..\cmake\..\third_party\eigen -IV:\bin\scripting\python\conda\envs\pytorch\include -Iv:\bin\scripting\python\conda\envs\pytorch\l
ib\site-packages\numpy\core\include -I..\torch\include -I..\cmake\..\third_party\cub -I"C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v10.2\include" -I..\caffe2 /DWIN32 /D_WINDOWS /GR  /w /EHa /MP 
/bigobj -openmp:experimental -DHAVE_AVX_CPU_DEFINITION -DHAVE_AVX2_CPU_DEFINITION /MD /O2 /Ob2  /w /EHa /MP /bigobj   -DCUDA_HAS_FP16=1 -DUSE_GCC_GET_CPUID -DUSE_AVX -DUSE_AVX2 -DTH_HAVE_THREAD /Z7 /EHa
 /DNOMINMAX /wd4267 /wd4251 /wd4522 /wd4838 /wd4305 /wd4244 /wd4190 /wd4101 /wd4996 /wd4275 /bigobj -O2 -DCAFFE2_BUILD_MAIN_LIB -DONNX_BUILD_MAIN_LIB -std:c++14 /showIncludes /Focaffe2\CMakeFiles\torch_
cpu.dir\core\blob_serialization.cc.obj /Fdcaffe2\CMakeFiles\torch_cpu.dir\ /FS -c ..\caffe2\core\blob_serialization.cc                                                                                    
V:\src\git\pytorch\src\pytorch\caffe2/core/context_base.h(92): error C2338: CopyToCPU requires fundamental types                                                                                          
..\caffe2\core\blob_serialization.cc(602): note: see reference to function template instantiation 'void at::BaseContext::CopyToCPU<c10::Half>(size_t,const T *,T *)' being compiled                       
        with                                                                                                                                                                                              
        [                                                                                                                                                                                                 
            T=c10::Half                                                                                                                                                                                   
        ]                                                                                                                                                                                                 
[102/995] Building CXX object caffe2\CMakeFiles\torch_cpu.dir\opt\onnxifi_op.cc.obj                                                                                                                       
ninja: build stopped: subcommand failed.                                                                                                                                                                  
Traceback (most recent call last):                                                                                                                                                                        
  File "setup.py", line 755, in <module>                                                                                                                                                                  
    build_deps()                                                                                                                                                                                          
  File "setup.py", line 316, in build_deps                                                                                                                                                                
    cmake=cmake)                                                                                                                                                                                          
  File "v:\src\git\pytorch\src\pytorch\tools\build_pytorch_libs.py", line 62, in build_caffe2                                                                                                             
    cmake.build(my_env)                                                                                                                                                                                   
  File "v:\src\git\pytorch\src\pytorch\tools\setup_helpers\cmake.py", line 337, in build                                                                                                                  
    self.run(build_args, my_env)                                                                                                                                                                          
  File "v:\src\git\pytorch\src\pytorch\tools\setup_helpers\cmake.py", line 141, in run                                                                                                                    
    check_call(command, cwd=self.build_dir, env=env)                                                                                                                                                      
  File "v:\bin\scripting\python\conda\envs\pytorch\lib\subprocess.py", line 347, in check_call                                                                                                            
    raise CalledProcessError(retcode, cmd)                                                                                                                                                                
subprocess.CalledProcessError: Command '['cmake', '--build', '.', '--target', 'install', '--config', 'Release', '--', '-j', '8']' returned non-zero exit status 1.
```                                       `


cc @peterjc123

[peterjc123]

So the compiler is complaining about std::is_fundamental<c10::Half> being false. Is that true, @ezyang?

[peterjc123]

Well, it should be true because it was set here: https://github.com/pytorch/pytorch/blob/master/c10/util/typeid.h#L51.

[peterjc123]

The following code gets 0 as an output in VS 2019 16.4, but 1 in VS 2017. It is likely a VS bug. Issue: https://developercommunity.visualstudio.com/content/problem/848198/cannot-customize-is-fundamental-for-a-new-type.html

#include <iostream>
#include <type_traits>

struct a {
	int b;
};

namespace std {
	template<>
	struct is_fundamental<a> : std::true_type {};
}

int main() {
	std::cout << std::is_fundamental<a>::value << std::endl;
}

[ezyang]

Oof. So maybe we should polyfill is_fundamental with our own implementation to work around the problem.

[peterjc123]

This is the reply from MS. I think we should make the change.

See the C++ standard, [meta] / p4

Unless otherwise specified, the behavior of a program that adds specializations for any of the templates
specified in this subclause [meta] is undefined.

[traits]

Unless otherwise specified, the behavior of a program that adds specializations for any of the templates
specified in this subclause [meta] is undefined.

This is a bit strange, I found this sentence only in newer drafts of the standard, it is not even part of C++ 2017. So, the current cmake value CMAKE_CXX_STANDARD 14 should be enough, shouldn't it? Otherwise, either cmake's or Visual Studio's behavior is incorrect.