Windows Visual Studio error with Eigen

[resonance20]

I get the following error with python 3.6.4 on windows 10 while using pip install:

Collecting pydensecrf
  Using cached https://files.pythonhosted.org/packages/31/5a/1c2ab48e8019d282c128bc5c621332267bb954d32eecdda3ba57306b1551/pydensecrf-1.0rc3.tar.gz
Building wheels for collected packages: pydensecrf
  Running setup.py bdist_wheel for pydensecrf ... error
  Complete output from command c:\users\brain\miniconda3\python.exe -u -c "import setuptools, tokenize;__file__='C:\\Users\\brain\\AppData\\Local\\Temp\\pip-install-wj25x65h\\pydensecrf\\setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" bdist_wheel -d C:\Users\brain\AppData\Local\Temp\pip-wheel-r3h92lnu --python-tag cp36:
  running bdist_wheel
  running build
  running build_py
  creating build
  creating build\lib.win-amd64-3.6
  creating build\lib.win-amd64-3.6\pydensecrf
  copying pydensecrf\utils.py -> build\lib.win-amd64-3.6\pydensecrf
  copying pydensecrf\__init__.py -> build\lib.win-amd64-3.6\pydensecrf
  running build_ext
  building 'pydensecrf.eigen' extension
  creating build\temp.win-amd64-3.6
  creating build\temp.win-amd64-3.6\Release
  creating build\temp.win-amd64-3.6\Release\pydensecrf
  C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\VC\Tools\MSVC\14.13.26128\bin\HostX86\x64\cl.exe /c /nologo /Ox /W3 /GL /DNDEBUG /MD -Ipydensecrf/densecrf/include -Ipydensecrf -Ic:\users\brain\miniconda3\include -Ic:\users\brain\miniconda3\include "-IC:\Program Files (x86)\Microsoft Visual Studio\2017\Community\VC\Tools\MSVC\14.13.26128\ATLMFC\include" "-IC:\Program Files (x86)\Microsoft Visual Studio\2017\Community\VC\Tools\MSVC\14.13.26128\include" "-IC:\Program Files (x86)\Windows Kits\NETFXSDK\4.6.1\include\um" "-IC:\Program Files (x86)\Windows Kits\10\include\10.0.16299.0\ucrt" "-IC:\Program Files (x86)\Windows Kits\10\include\10.0.16299.0\shared" "-IC:\Program Files (x86)\Windows Kits\10\include\10.0.16299.0\um" "-IC:\Program Files (x86)\Windows Kits\10\include\10.0.16299.0\winrt" "-IC:\Program Files (x86)\Windows Kits\10\include\10.0.16299.0\cppwinrt" /EHsc /Tppydensecrf/eigen.cpp /Fobuild\temp.win-amd64-3.6\Release\pydensecrf/eigen.obj
  eigen.cpp
  c:\users\brain\appdata\local\temp\pip-install-wj25x65h\pydensecrf\pydensecrf\densecrf\include\eigen\src/Core/VectorBlock.h(120): error C2373: 'Eigen::DenseBase<Derived>::segment': redefinition; different type modifiers
  c:\users\brain\appdata\local\temp\pip-install-wj25x65h\pydensecrf\pydensecrf\densecrf\include\eigen\src/Core/DenseBase.h(291): note: see declaration of 'Eigen::DenseBase<Derived>::segment'
  c:\users\brain\appdata\local\temp\pip-install-wj25x65h\pydensecrf\pydensecrf\densecrf\include\eigen\src/Core/VectorBlock.h(121): error C2447: '{': missing function header (old-style formal list?)
  c:\users\brain\appdata\local\temp\pip-install-wj25x65h\pydensecrf\pydensecrf\densecrf\include\eigen\src/Core/VectorBlock.h(152): error C2373: 'Eigen::DenseBase<Derived>::head': redefinition; different type modifiers
  c:\users\brain\appdata\local\temp\pip-install-wj25x65h\pydensecrf\pydensecrf\densecrf\include\eigen\src/Core/DenseBase.h(294): note: see declaration of 'Eigen::DenseBase<Derived>::head'
  c:\users\brain\appdata\local\temp\pip-install-wj25x65h\pydensecrf\pydensecrf\densecrf\include\eigen\src/Core/VectorBlock.h(153): error C2447: '{': missing function header (old-style formal list?)
  c:\users\brain\appdata\local\temp\pip-install-wj25x65h\pydensecrf\pydensecrf\densecrf\include\eigen\src/Core/VectorBlock.h(184): error C2373: 'Eigen::DenseBase<Derived>::tail': redefinition; different type modifiers
  c:\users\brain\appdata\local\temp\pip-install-wj25x65h\pydensecrf\pydensecrf\densecrf\include\eigen\src/Core/DenseBase.h(297): note: see declaration of 'Eigen::DenseBase<Derived>::tail'
  c:\users\brain\appdata\local\temp\pip-install-wj25x65h\pydensecrf\pydensecrf\densecrf\include\eigen\src/Core/VectorBlock.h(185): error C2447: '{': missing function header (old-style formal list?)
  error: command 'C:\\Program Files (x86)\\Microsoft Visual Studio\\2017\\Community\\VC\\Tools\\MSVC\\14.13.26128\\bin\\HostX86\\x64\\cl.exe' failed with exit status 2

[lucasb-eyer]

We regularly get reports about difficulties on Windows. I personally can't help unfortunately, as I don't have access to windows anymore, but any PRs are welcome.

[resonance20]

Do you use a custom version of the eigen library here or is it a standard release? If standard, which version?

[resonance20]

Okay I found that using conda to install this library worked. Go figure.

[lucasb-eyer]

Thank you for getting back, I have added a note to the README.

[Tyllis]

I had the exact same issue on Window 10.
Resolved by running conda install -c conda-forge pydensecrf
https://anaconda.org/conda-forge/pydensecrf

[yzaretskiy]

In case folks don't want to use conda, I was able to resolve this particular issue by cloning the master branch, replacing the included Eigen library with its most recent version (3.3.5 as of today), and then installing pydensecrf with python setup.py install.

[tansyl]

Hi @lucasb-eyer , after looking through all the related threads, updating Eigen library to a newer version solved my case (I used 3.3.5). would you please update the package included or add a note to the README? I feel that it might eliminate the remaining windows installation issues. Thanks!

[mohammadreza-sheykhmousa]

I had the exact same issue on Window 10.
Resolved by running conda install -c conda-forge pydensecrf
https://anaconda.org/conda-forge/pydensecrf

Thanks @Tyllis this solved my problem as well.

[daddydrac]

Conda install fails ->

Collecting package metadata (repodata.json): done
Solving environment: failed with initial frozen solve. Retrying with flexible solve.

[ElonGaties]

@salinaaaaaa did you fix that?