Boost.Python Quickstart Linker Errors

Question

I'm just trying to follow the instructions here to get the Quickstart example working. I am on Windows 7 and trying to use MSVC. I have Python 2.7 installed.

What I have done:

• Download boost_1_57_0.zip and extract to C:\\boost_1_57_0 .

• From command prompt in C:\\boost_1_57_0 , run:

   bootstrap 

  then:

   .\\b2 

  as per the instructions under 5.1 here . After this I have a message saying "The Boost C++ Libraries were successfully built!".

• Add C:\\boost_1_57_0 to my path. The instructions don't say to do this, but since they want me to invoke bjam, and that's where it lives, I assume I need to do this.
• Modify C:\\boost_1_57_0\\libs\\python\\example\\quickstart\\boost-build.jam so that the path is boost-build ../../../../tools/build/src ; and not boost-build ../../../../tools/build/v2 ; . This is as per the instructions here since the original path is wrong and if you don't do this the bjam invocation fails.

• CD into C:\\boost_1_57_0\\libs\\python\\example\\quickstart and run:

   bjam toolset=msvc --verbose-test test 

The output I get is firstly:

...patience...
...patience...
...found 1926 targets...
...updating 55 targets...
common.mkdir bin
common.mkdir bin\test_ext.test
common.mkdir bin\test_ext.test\msvc-12.0
common.mkdir bin\test_ext.test\msvc-12.0\debug
common.mkdir bin\test_ext.test\msvc-12.0\debug\threading-multi
common.mkdir bin\msvc-12.0
common.mkdir bin\msvc-12.0\debug
common.mkdir bin\msvc-12.0\debug\threading-multi
compile-c-c++ bin\msvc-12.0\debug\threading-multi\extending.obj
extending.cpp
c:\python27\include\pymath.h(22) : warning C4273: 'round' : inconsistent dll linkage
    C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\INCLUDE\math.h(516) : see previous definition of 'round'
C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\INCLUDE\xtgmath.h(190) : warning C4273: '_hypot' : inconsistent dll linkage

followed by a long list of other header file entries, each complaining about inconsistent dll linkage, and then at the end a bunch of errors, highlights of which include:

LINK : fatal error LNK1207: incompatible PDB format in 'C:\boost_1_57_0\libs\python\example\quickstart\bin\msvc-12.0\debug\threading-multi\extending.pdb'; delete and rebuild

...failed msvc.link.dll bin\msvc-12.0\debug\threading-multi\extending.pyd bin\msvc-12.0\debug\threading-multi\extending.pdb...
...removing bin\msvc-12.0\debug\threading-multi\extending.pdb

LINK : warning LNK4001: no object files specified; libraries used
LINK : error LNK2001: unresolved external symbol _mainCRTStartup
bin\test_embed.test\msvc-12.0\debug\threading-multi\test_embed.exe : fatal error LNK1120: 1 unresolved externals

...failed msvc.link bin\test_embed.test\msvc-12.0\debug\threading-multi\test_embed.exe bin\test_embed.test\msvc-12.0\debug\threading-multi\test_embed.pdb...
...removing bin\test_embed.test\msvc-12.0\debug\threading-multi\test_embed.pdb
...skipped <pbin\test_embed.test\msvc-12.0\debug\threading-multi>test_embed.run for lack of <pbin\test_embed.test\msvc-12.0\debug\threading-multi>test_embed.exe...
...failed updating 4 targets...

Any ideas?

Answer 1

The problem is still present with 1.59. I've managed to get Boost.Build working again by editing the file:

D:\boost\boost_1_59_0\tools\build\src\tools\msvc.jam

I made two changes:

1. Change this (lines #1351-1355):

     generators.register [ new msvc-linking-generator msvc.link.dll : OBJ SEARCHED_LIB STATIC_LIB IMPORT_LIB : SHARED_LIB IMPORT_LIB : <toolset>msvc <suppress-import-lib>false ] ; generators.register [ new msvc-linking-generator msvc.link.dll : OBJ SEARCHED_LIB STATIC_LIB IMPORT_LIB : SHARED_LIB : <toolset>msvc <suppress-import-lib>true ] ; 

   to:

     generators.register [ new msvc-linking-generator msvc.link.dll : OBJ SEARCHED_LIB STATIC_LIB IMPORT_LIB : SHARED_LIB IMPORT_LIB : <toolset>msvc ] ; 

2. Remove this line (#1472):

     toolset.flags msvc.link.dll LINKFLAGS <suppress-import-lib>true : /NOENTRY ; 

I've tested this on Win7 with VS2012 and Python 2.7.

Answer 2

I also saw that incompatible PDB format issue, but only with 1.57, which (since the Boost.Python source is the same for 1.57 and 1.55 and I can get it working on 1.55) I'm guessing is somehow related to the changes in the boost::build path.

I've documented what I had to do to get it working with 1.55, maybe that will be some help.

Answer 3

Madness I tell you.

Anyway, I finally succeeded in building the quickstart example on boost_1_68_0. A quick guidethrough:

• (On windows, visual studio 2017 and SDK installed, python 3.5 installed)
• Download and extract it in like C:\\boost_1_68_0
• Run bootstrap.bat
• Build the boost-python libraries:

C:\\boost_1_68_0>.\\b2 --with-python -j4

• Go to C:\\boost_1_68_0\\libs\\python\\example, and fix the Jamroot to find your header files

  project : requirements <include>C:\\\\boost_1_68_0 <library>boost_python 

• Fix the tools\\build\\src\\tools\\msvc.jam file in the way Ralph in this post commented
• As described here , patch embedding.cpp and extending.cpp by adding "#define BOOST_PYTHON_STATIC_LIB" as the first line everywhere
• Copy the built python-boost libs (from C:\\boost_1_68_0\\stage\\lib) to the quickstart folder
• Finally build it

C:\\boost_1_68_0\\libs\\python\\example\\quickstart>..\\..\\..\\..\\b2.exe -j4

Again, this is -crazy- complex. All the other stuff builds just fine, but the python linkage is really broken. Anyway, in case anyone tries, hope this helps.