CARLA 0.9.7 does not generate a python library on Windows 10

[gokhanbarisaker]

Hi,

Running make PythonAPI claims to complete successfully with following output.

-[BuildPythonAPI]: Carla lib for python has been successfully installed in "C:/path/to/Workspace/Cpp/carla/PythonAPI\carladist"! 

At first sight, the mixed usage of path separators looks suspicious. However, even if I ignore the forward slashes (i.e., /) by replacing them with backwards slash (i.e.,), there is no carladist in that path.

As user, I would expect there is an actual output in the highlighted path given with the build output.

Test environment

Windows 10 1909
Visual Studio 2017
Unreal Engine 4.22.3
Python 3.7.4.final.0
GNU Make 4.2.1
cmake version 3.12.18081601-MSVC_2
carla 0.9.7 (b9fbbf7)

[CodingdAwn]

same problem and i have some link error
but finally output successful
-[BuildPythonAPI]: Carla lib for python has been successfully installed in "D:/project/carla/PythonAPI\carladist"
checking and it's nothing generated

lease\source/libcarla\libcarla.cp38-win32.exp
libcarla.obj : error LNK2001: 无法解析的外部符号 __imp_PyBool_FromLong
libboost_python38-vc141-mt-x64-1_69.lib(class.obj) : error LNK2001: 无法解析的外部符号 __imp_PyBool_FromLong
libcarla.obj : error LNK2001: 无法解析的外部符号 __imp_PySlice_Type
libboost_python38-vc141-mt-x64-1_69.lib(function_doc_signature.obj) : error LNK2001: 无法解析的外部符号 __imp_PyErr_Occurred
libboost_python38-vc141-mt-x64-1_69.lib(stl_iterator.obj) : error LNK2001: 无法解析的外部符号 __imp_PyErr_Occurred
libboost_python38-vc141-mt-x64-1_69.lib(enum.obj) : error LNK2001: 无法解析的外部符号 __imp_PyErr_Occurred
libboost_python38-vc141-mt-x64-1_69.lib(pickle_support.obj) : error LNK2001: 无法解析的外部符号 __imp_PyErr_Occurred
libboost_python38-vc141-mt-x64-1_69.lib(str.obj) : error LNK2001: 无法解析的外部符号 __imp_PyErr_Occurred
libcarla.obj : error LNK2001: 无法解析的外部符号 __imp_PyErr_Occurred
libboost_python38-vc141-mt-x64-1_69.lib(builtin_converters.obj) : error LNK2001: 无法解析的外部符号 __imp_PyErr_Occurred
libboost_python38-vc141-mt-x64-1_69.lib(list.obj) : error LNK2001: 无法解析的外部符号 __imp_PyErr_Occurred
libboost_python38-vc141-mt-x64-1_69.lib(function.obj) : error LNK2001: 无法解析的外部符号 __imp_PyErr_Occurred
libcarla.obj : error LNK2001: 无法解析的外部符号 __imp_PyEval_SaveThread
libboost_python38-vc141-mt-x64-1_69.lib(pickle_support.obj) : error LNK2001: 无法解析的外部符号 __imp_PyExc_RuntimeError
libcarla.obj : error LNK2001: 无法解析的外部符号 __imp_PyExc_RuntimeError
libboost_python38-vc141-mt-x64-1_69.lib(errors.obj) : error LNK2001: 无法解析的外部符号 __imp_PyExc_RuntimeError
libboost_python38-vc141-mt-x64-1_69.lib(class.obj) : error LNK2001: 无法解析的外部符号 __imp_PyExc_RuntimeError
libboost_python38-vc141-mt-x64-1_69.lib(function.obj) : error LNK2001: 无法解析的外部符号 __imp_PyExc_RuntimeError
libcarla.obj : error LNK2001: 无法解析的外部符号 __imp_PyLong_FromLong
libboost_python38-vc141-mt-x64-1_69.lib(enum.obj) : error LNK2001: 无法解析的外部符号 __imp_PyLong_FromLong
libboost_python38-vc141-mt-x64-1_69.lib(function_doc_signature.obj) : error LNK2001: 无法解析的外部符号 __imp_PyLong_FromLong

[alexmargulis]

I think that this is a known issue, therefore there are no compiled versions greater than 0.9.5. for Windows.
I'm personally stuck with these errors:

Creating library build\temp.win-amd64-3.6\Release\source/libcarla\libcarla.cp36-win_amd64.lib and object build\temp.win-amd64-3.6\Release\source/libcarla\libcarla.cp36-win_amd64.exp
libpng.lib(pngwrite.obj) : error LNK2001: unresolved external symbol deflate
libpng.lib(pngwutil.obj) : error LNK2001: unresolved external symbol deflate
libpng.lib(pngwrite.obj) : error LNK2001: unresolved external symbol deflateEnd
libpng.lib(png.obj) : error LNK2001: unresolved external symbol inflateReset
libpng.lib(pngrutil.obj) : error LNK2001: unresolved external symbol inflateReset
libpng.lib(png.obj) : error LNK2001: unresolved external symbol crc32
libpng.lib(pngread.obj) : error LNK2001: unresolved external symbol inflate
libpng.lib(pngrutil.obj) : error LNK2001: unresolved external symbol inflate
libpng.lib(pngread.obj) : error LNK2001: unresolved external symbol inflateEnd
libpng.lib(pngread.obj) : error LNK2001: unresolved external symbol inflateInit_
libpng.lib(pngwutil.obj) : error LNK2001: unresolved external symbol deflateReset
libpng.lib(pngwutil.obj) : error LNK2001: unresolved external symbol deflateInit2_
build\lib.win-amd64-3.6\carla\libcarla.cp36-win_amd64.pyd : fatal error LNK1120: 9 unresolved externals
error: command 'C:\Program Files (x86)\Microsoft Visual Studio\2017\BuildTools\VC\Tools\MSVC\14.16.27023\bin\HostX86\x64\link.exe' failed with exit status 1120

-[BuildPythonAPI]: Carla lib for python has been successfully installed in "D:/carla/PythonAPI\carladist"!

[alexmargulis]

There is a workaround for this problem - run PythonAPI 0.9.7 compiled for linux in WSL

[jeffreykxiao]

The message is definitely confusing, because the .egg file is saved to carla/PythonAPI/carla/dist. It's a fairly innocuous error in the build python API batch script. Thanks for posting this, I also had issues with PythonAPI building on windows (though I was able to resolve my problems). I will be submitting a PR soon to resolve some problems I discovered while looking into this issue.

[jeffreykxiao]

I can't say for sure that #2348 will fix all of the issues mentioned by users here but I hope it will help. I encountered many issues when I upgraded an earlier version where I had an installed PythonAPI. In the past I had used make clean but I didn't know that it wasn't working. With the change, make clean should remove any intermediate files messing with your build. make PythonAPI has always worked fine for me. I am using Win10 Pro x64, UE4.22.3, VS2017 w/ Native Tools x64 Prompt, python 3.6, Make for Windows 3.81

[arguskos]

@alexmargulis Can you please explain how to run it. I mean I can compile it under wsl but it will not run client because there is no support for graphics in wsl as I understand and you can't launch it from windows as well?

[alexmargulis]

@arguskos This worked for me:
microsoft/WSL#2855 (comment)

[wiescho]

@CodingdAwn I managed to build the PythonAPI by deleting the headers option in the boost build script Util\InstallersWin\install_boost.bat
in my case with this option boost won't build the libboost_python lib

echo %FILE_N% Building...
b2 -j%NUMBER_OF_ASYNC_JOBS%^
--layout=versioned^
--build-dir=.\build^
--with-system^
--with-filesystem^
--with-python^
--with-date_time^
architecture=x86^
address-model=64^
toolset=%TOOLSET%^
variant=release^
link=static^
runtime-link=shared^
threading=multi^
--prefix="%BOOST_INSTALL_DIR%"^
--libdir="%BOOST_LIB_DIR%"^
--includedir="%BOOST_INSTALL_DIR%"^
install

quote from http://boost.2283326.n4.nabble.com/doc-b2-headers-td4702968.html

b2 headers is not really intended for end users.
It's only relevant when working from git as the
packaged releases have all the headers moved into
boost/ to begin with.