id summary reporter owner description type status milestone component version severity resolution keywords cc 12266 Visual Studio 2015 Express for Desktop and 64-bit builds carles.cufi@… "When building Boost statically as a set of 64-bit static libraries, I have found that using the ""usual"" Command Prompt doesn't yield 64-bit objects, but rather 32-bit ones. The build commands I am issuing are: bootstrap.bat b2 toolset=msvc-14.0 address-model=64 link=static --with-thread --with-system --with-regex --with-date_time --with-chrono If I open a ""Developer Command Prompt"" (equivalent to executing %comspec% /k """"C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\Tools\VsDevCmd.bat"""") and then build with the commands above, the libraries generated are 32-bit. If I open a ""standard"" command prompt (equivalent to %comspec% /k """"C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat"""" x86) and then build with the commands above, the libraries generated are 32-bit. Finally, if I open a ""Visual Studio 2015 x86 x64 Cross Tools Command Prompt"" (equivalent to %comspec% /k """"C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat"""" x86_amd64) and then build with the commands above, the libraries generated are 64-bit. This is in my opinion a problem because of two reasons: 1) This contradicts the documentation in: http://www.boost.org/build/doc/html/bbv2/reference/tools.html#bbv2.reference.tools.compiler.msvc where it says: ""Configure you compiler as usual. If you provide a path to the compiler explicitly, provide the path to the 32-bit compiler. If you try to specify the path to any of 64-bit compilers, configuration will not work."" The usual configuration on Windows is the standard Developer Command Prompt. 2) The build doesn't fail or complain that it cannot generate 64-bit binaries, and instead silently disregards the ""address-model=64"" option and generates 32-bit binaries. Please note that with other tools (CMake for example) one can build both 32 and 64-bit binaries from a ""standard"" command prompt (i.e. no need to invoke vcvarsall.bat x86_amd64). " Bugs new To Be Determined Building Boost Boost 1.61.0 Problem