I am new to building boost, so I apologize if this is an uninformed question. I was able to build the boost 1.49 and 1.50 libraries using qcc 4.4.2 (QNX's gcc 4.4.2) without major issues. Boost 1.51 has added a new wrinkle, and I'm not sure how to address it. Here's a snipit from the build.log. Any help is appreciated. error: No best alternative for libs/context/build/asm_context_sources next alternative: required properties: <abi>aapcs <architecture>arm <binary-format>elf <toolset>gcc not matched next alternative: required properties: <abi>aapcs <architecture>arm <binary-format>elf not matched next alternative: required properties: <abi>o32 <architecture>mips1 <binary-format>elf <toolset>gcc not matched next alternative: required properties: <abi>o32 <architecture>mips1 <binary-format>elf not matched next alternative: required properties: <abi>sysv <address-model>32 <architecture>power <binary-format>elf <toolset>gcc not matched next alternative: required properties: <abi>sysv <address-model>32 <architecture>power <binary-format>elf not matched next alternative: required properties: <abi>sysv <address-model>64 <architecture>power <binary-format>elf <toolset>gcc not matched next alternative: required properties: <abi>sysv <address-model>64 <architecture>power <binary-format>elf not matched next alternative: required properties: <abi>sysv <address-model>32 <architecture>x86 <binary-format>elf <toolset>gcc not matched next alternative: required properties: <abi>sysv <address-model>32 <architecture>x86 <binary-format>elf <toolset>intel not matched next alternative: required properties: <abi>sysv <address-model>32 <architecture>x86 <binary-format>elf not matched next alternative: required properties: <abi>sysv <address-model>32 <architecture>x86 <binary-format>mach-o <target-os>darwin <toolset>gcc not matched next alternative: required properties: <abi>sysv <address-model>32 <architecture>x86 <binary-format>mach-o <target-os>darwin <toolset>intel not matched next alternative: required properties: <abi>sysv <address-model>32 <architecture>x86 <binary-format>mach-o <target-os>darwin not matched next alternative: required properties: <abi>ms <address-model>32 <architecture>x86 <binary-format>pe <target-os>windows <toolset>intel not matched next alternative: required properties: <abi>ms <address-model>32 <architecture>x86 <binary-format>pe <target-os>windows <toolset>msvc not matched next alternative: required properties: <abi>ms <address-model>32 <architecture>x86 <binary-format>pe <target-os>windows <toolset>gcc not matched next alternative: required properties: <abi>sysv <address-model>64 <architecture>x86 <binary-format>elf <toolset>gcc not matched next alternative: required properties: <abi>sysv <address-model>64 <architecture>x86 <binary-format>elf <toolset>intel not matched next alternative: required properties: <abi>sysv <address-model>64 <architecture>x86 <binary-format>elf not matched next alternative: required properties: <abi>sysv <address-model>64 <architecture>x86 <binary-format>mach-o <target-os>darwin <toolset>gcc not matched next alternative: required properties: <abi>sysv <address-model>64 <architecture>x86 <binary-format>mach-o <target-os>darwin <toolset>intel not matched next alternative: required properties: <abi>sysv <address-model>64 <architecture>x86 <binary-format>mach-o <target-os>darwin not matched next alternative: required properties: <abi>ms <address-model>64 <architecture>x86 <binary-format>pe <target-os>windows <toolset>intel not matched next alternative: required properties: <abi>ms <address-model>64 <architecture>x86 <binary-format>pe <target-os>windows <toolset>msvc not matched next alternative: required properties: <abi>ms <address-model>64 <architecture>x86 <binary-format>pe <target-os>windows <toolset>gcc not matched