In my jam file I have: import ../../predef/check/predef : check require : predef-check predef-require ; and in the requirments section of various Boost Build built-in rules I have: [ predef-check "BOOST_COMP_GNUC >= 4.3" : <cxxflags>-std=c++0x ] When I try to process my jamfile I get numerous warnings along the line of:

C:/Programming/VersionControl/modular-boost/libs/vmd/test\../../predef/check/pre def.jam:61: in predef-check warning: object is empty Jamfile.v2:51: in modules.load C:/Programming/VersionControl/modular-boost/tools/build/src/build\project.jam:32 5: in load-jamfile C:/Programming/VersionControl/modular-boost/tools/build/src/build\project.jam:64 : in load C:/Programming/VersionControl/modular-boost/tools/build/src/build\project.jam:14 5: in project.find C:/Programming/VersionControl/modular-boost/tools/build/src\build-system.jam:535 : in load C:\Programming\VersionControl\modular-boost\tools\build\src/kernel\modules.jam:2 89: in import C:\Programming\VersionControl\modular-boost\tools\build\src/kernel/bootstrap.jam :139: in boost-build C:\Programming\VersionControl\modular-boost\boost-build.jam:17: in module scope C:/Programming/VersionControl/modular-boost/libs/vmd/test\../../predef/check/pre def.jam:61: in predef-check warning: object is empty Jamfile.v2:52: in modules.load

followed eventually by:

C:\Programming\VersionControl\modular-boost\boost-build.jam:17: in module scope Performing configuration checks

- 32-bit : yes (cached) - arm : no (cached) - mips1 : no (cached) - power : no (cached) - sparc : no (cached) - x86 : yes (cached) - symlinks supported : yes C:/Programming/VersionControl/modular-boost/tools/build/src/kernel\modules.jam:1 07: in modules.call-in *** argument error * rule ../../predef/check/predef.predef_check_action ( targets + : sources + : p rops * ) * called with: ( 8bab483dffdbedc6438ba8af0f25a37e.txt : : <abi>ms <actio n>@../../predef/check/predef%../../predef/check/predef.predef_check_action <addr ess-model>32 <architecture>x86 <asynch-exceptions>off <auto-index-internal>off < auto-index-no-duplicates>off <auto-index-section-names>on <auto-index-verbose>of f <auto-index>off <binary-format>pe <debug-store>object <debug-symbols>on <doxyg en.doxproc.index>no xsltproc <embed-manifest>on <exception-ha ndling>on <extern-c-nothrow>off <format>html <hardcode-dll-paths>true <host-os>w indows <inlining>off <install-dependencies>off <link>shared <log-api>generic <mi dl-robust>yes <midl-stubless-proxy>yes <optimization>off <os>NT <pch>on <predef- expression>BOOST_COMP_GNUC >= 4.3 <preserve-test-targets>on <profiling>off <pyth on-debugging>off C:/Utilities/Python278_32\python <python>2. 7 <rtti>on <runtime-debugging>on <runtime-link>shared <stdlib>native <strip>off <suppress-import-lib>false <symlink-location>project-relative <target-os>windows on <threadapi>win32 <threading>single toolset-gcc:flavorming w toolset-gcc:version4.9.2 <toolset>gcc <user-interface>console <variant>debug <warnings-as-errors>off <warnings>on <windows-api>desktop : : : : : : : : : : : : : : : ) * missing argument sources C:/Programming/VersionControl/modular-boost/libs/vmd/test\../../predef/check/pre def.jam:99:see definition of rule '../../predef/check/predef.predef_check_action ' being called C:/Programming/VersionControl/modular-boost/tools/build/src/util\indirect.jam:98 : in indirect.call C:/Programming/VersionControl/modular-boost/tools/build/src/build\virtual-target .jam:798: in class@action.actualize C:/Programming/VersionControl/modular-boost/tools/build/src/build\virtual-target .jam:311: in actualize-action

etc. Any ideas of what is wrong ? Without the use of predef-check everything is OK. I have the latest 'develop' for predef and Boost build. I am trying to set gcc in c++11 mode for gcc 4.3 on up in my VMD tests.