id,summary,reporter,owner,description,type,status,milestone,component,version,severity,resolution,keywords,cc
7101,b2 defines multiple isysroot on Mac OSX 10.6 when targeting SDK versions earlier than 10.6,mikko.vainio@…,Vladimir Prus,"Building Boost 1.50.0 on Mac OSX 10.6 included multiple SDK versions when targeting SDK versions 10.5 adn/or 10.4;

./b2 toolset=darwin link=static threading=multi stage --with-program_options architecture=combined macosx-version=10.5 macosx-version-min=10.5 -d3

produces

    ""g++""  -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -gdwarf-2 -fexceptions -isysroot /Developer/SDKs/MacOSX10.5.sdk -mmacosx-version-min=10.5 -isysroot /Developer/SDKs/MacOSX10.6.sdk -mmacosx-version-min=10.5 -arch i386 -arch ppc  -DBOOST_ALL_NO_LIB=1 -DNDEBUG  -I""."" -c -o ""bin.v2/libs/program_options/build/darwin-4.2.1/release/architecture-combined/link-static/macosx-version-min-10.5/macosx-version-10.5/threading-multi/cmdline.o"" ""libs/program_options/src/cmdline.cpp""

and targeting 10.4 SDK

./b2 toolset=darwin link=static threading=multi stage --with-program_options architecture=combined macosx-version=10.4 macosx-version-min=10.4 -d3

produces

    ""g++""  -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -gdwarf-2 -fexceptions -isysroot /Developer/SDKs/MacOSX10.4u.sdk -mmacosx-version-min=10.4 -isysroot /Developer/SDKs/MacOSX10.5.sdk -mmacosx-version-min=10.4 -isysroot /Developer/SDKs/MacOSX10.6.sdk -mmacosx-version-min=10.4 -arch i386 -arch ppc  -DBOOST_ALL_NO_LIB=1 -DNDEBUG  -I""."" -c -o ""bin.v2/libs/program_options/build/darwin-4.2.1/release/architecture-combined/link-static/macosx-version-min-10.4/macosx-version-10.4/threading-multi/cmdline.o"" ""libs/program_options/src/cmdline.cpp""

that is, {{{isysroot}}} is defined multiple times. That apparently causes the latest SDK to be used, which leads to linker errors when a project built against an earlier SDK tries to link Boost.

A quick workaround is to hide the later SDK from b2:
{{{
sudo mv /Developer/SDKs/MacOSX10.6.sdk /Developer/SDKs/bak.MacOSX10.6.sdk
}}}
then run b2 as usual, and finally revert the renaming of the SDK
{{{
sudo mv /Developer/SDKs/bak.MacOSX10.6.sdk /Developer/SDKs/MacOSX10.6.sdk
}}}

",Bugs,new,To Be Determined,build,Boost 1.50.0,Problem,,,paleozogt@…