Re: The state of modular Boost

From: Peter Dimov (pdimov_at_[hidden])
Date: 2025-04-16 11:14:07

John Maddock wrote:
> First off, thank you for this effort, we really DO all appreciate this, however I
> do have some questions and concerns:
> 
> 1) Documentation: recently CI for Boost.Math completely broke and despite 3
> or us looking at it, we couldn't figure out why. Commenting out random stuff,
> I found that these project requirements were causing the issue:
> 
> project
>      : requirements
>        <library>/boost/math//boost_math
>        <library>/boost/multiprecision//boost_multiprecision
>        <library>/boost/test//included
>        <library>/boost/type_index//boost_type_index
>        <library>/boost/ublas//boost_ublas
> 
> If I removed them then everything started working again, so assuming that
> they were ancient cruft that was no longer needed I removed them. Woohoo,
> CI works again and we can get on with fixing some bugs, except now I realize
> these were part of the modular boost support code, so
> *probably* I've broken something else somewhere else, but I have no idea
> what.  Adding some boilerplate comments:
...
> would have helped a lot.

Listing dependencies in project requirements is a cheat and generally not
what one wants in any non-trivial Jamfile (same goes for build.jam). In
CMake parlance, which is what more people speak today than b2, this
corresponds to using link_libraries instead of target_link_libraries.

Unfortunately we have a lot of libraries containing those now. I've been
fixing them in the PRs I merged, but I can't be expected to go over
everything else.