We have a problem with gcc: thread support gets forced on in order to be consistent with libstdc++ (long story), and there was a user-request for a helpful message so that users would know that they *may* end up needing -lpthread.
BTW, I was told that if boost/config.hpp is included before any system headers, it will still be able to use _REENTRANT to detect if -pthread was specified on the command line.
Yep, but if -pthread is specified on the command line, then presumably the user really does want thread safe code :-)
My gut feeling is to just take the warning out for this release, longer term: Vladimir is there any macro that gets defined by the bjam build process, something like BOOST_BJAM_BUILD, so the code knows when it's being built by the bjam test system? Any other helpful suggestions welcomed....
No, I don't know any. How would that help? I'm not sure if such macro can be easily added in Boost.Build v1. In V2 it's one-line change to top-level Jamfile, so I hope V2 will be ready to replace V1 after we've done with the release.
I was just thinking out loud really, that maybe we could automatically suppress things like this whenever we're building with bjam, but you're right it doesn't really solve the issue. John.