On Thu, 27 Sep 2018 at 05:18, Peter Dimov via Boost
Stefan Seefeld wrote:
Indeed: While the above is a great starting point to support what I want, I don't want to loose the ability for BPL to be built (and tested) as part of the rest of Boost. I would thus prefer something that gives me the ability to choose the build strategy e.g. using some command-line option, including flag to be passed to the build (e.g., `b2 ... standalone=on`), rather than having to modify the (build) code.
Scanning for Jamroot to identify the project root is fundamental to Jam (the Perforce one). We could perhaps add something like
b2 --jamroot=.
that would act as if there were an empty Jamroot at . (or equivalently if the Jamfile at . were named Jamroot.)
Does it mean there could be two jamfile-s? libs/gil/Jamroot for standalone build libs/gil/Jamfile for in-Boost tree build and the latter is simply ignored in normal b2 run, ie. without --jamroot=. I think, this would be also very helpful to apply the Jamroot trick [1], recently presented to me by Steven Watanabe, to significantly speed up b2 startup procedures: """ Try inserting a Jamroot to block the extra work that Boost's Jamroot is doing automatically. This is a bad idea in general, as the aforementioned work is important, but it should be okay as long as you set up `b2 headers` beforehand and do not use any separately compiled boost libraries. """ [1] https://lists.boost.org/boost-build/2018/08/29977.php Best regards, -- Mateusz Loskot, http://mateusz.loskot.net