Hello, I'm trying to update from boost 1.61 to 1.62 on msvc for conda and encountered this error: [00:03:41] Performing configuration checks [00:03:41] [00:03:41] - 32-bit : yes ... [00:03:41] - x86 : yes [00:03:41] - symlinks supported : yes [00:03:41] - C++11 mutex : no [00:03:41] - Boost.Config Feature Check: cxx11_auto_declarations : no ... [00:03:42] - has_icu builds : no ... [00:03:43] - zlib : yes [00:03:43] error: at C:/conda/conda-bld/work/boost_1_62_0/tools/build/src/kernel\modules.jam:107 [00:03:43] error: Name clash for '<pbuildboost\boost\bin.v2\standalone\ac\msvc-9.0\release\link-static\threading-multi>main.obj' [00:03:43] error: [00:03:43] error: Tried to build the target twice, with property sets having [00:03:43] error: these incompatible properties: [00:03:43] error: [00:03:43] error: - <dll-path>C:\conda\envs\_build\Library\lib <library-path>C:\conda\envs\_build\Library\lib <xdll-path>C:\conda\envs\_build\Library\lib [00:03:43] error: - none [00:03:43] error: [00:03:43] error: Please make sure to have consistent requirements for these [00:03:43] error: properties everywhere in your project, especially for install [00:03:43] error: targets. [00:03:43] [00:03:43] Command failed: cmd.exe /c bld.bat [00:03:43] Command exited with code 1 Full logs are available here: https://ci.appveyor.com/project/conda-forge/boost-feedstock/build/1.0.36 I've got the same error for vc9, vc10 and vc14 for both 32 and 64bits. I configure with the exact same script I used for 1.61, here's the configure part: call bootstrap.bat .\b2 install ^ --build-dir=buildboost ^ --prefix=%LIBRARY_PREFIX% ^ toolset=msvc-%VSTRING%.0 ^ address-model=%ARCH% ^ variant=release ^ threading=multi ^ link=static,shared ^ -j%CPU_COUNT% ^ -s ZLIB_INCLUDE="%LIBRARY_INC%" ^ -s ZLIB_LIBPATH="%LIBRARY_LIB%" It can be seen there: https://github.com/conda-forge/boost-feedstock/blob/master/recipe/bld.bat I've not seen it reported in the trac tickets, did someone get the same error ? -- J Schueller