Thanks a lot Steve (and others). I figured out that the problem is the initial bootstrap does not pick anything from user-config.jam for our custom compiler.. it's all hard-coded in there. So when no gcc is available in PATH, (my case) it shows these wierd errors. Also understood that doesnt matter what compiler you build bootstrap with. So I just ensure that my gcc is in PATH for bootstrap to succeed, then the 2nd step picks the custom gcc from the jam file correctly. I guess this solves it for me. However if you only have a custom compiler inside some folder with a name like gcc-4-5-mine , then I guess you might need to create an alias, or edit the build.sh file inside tools/build/engine/v2 as pointed out by the stack overflow qn. Thanks again. -- View this message in context: http://boost.2283326.n4.nabble.com/Building-boost-with-custom-gcc-g-tp464105... Sent from the Boost - Users mailing list archive at Nabble.com.