I'm currently having a lot of problems with the regex regression test reports (http://www.meta-comm.com/engineering/boost-regression/developer/regex.html) that appear to be caused by bjam not noticing when a dependent header has changed (The problems do not appear if the tester does a clean rebuild each time). For example if I cd into libs/regex/example, and bjam credit_card_example to bring that target up to date, and then: touch ../../../boost/regex/v4/cpp*.hpp bjam credit_card_example then nothing gets rebuild (everything should be rebuilt!). However as soon as I touch a source file: touch ../src/cpp*.cpp bjam credit_card_example Then the touched source files do at least get rebuilt. It would really really help if this could get fixed: at present some of our regression test reports are basically worthless - they may be either failing or *passing* incorrectly for no reason except that bjam has just decided not to rebuild them! Many thanks, John.