[Boost-build] Too much warning noise

Subject: [Boost-build] Too much warning noise
From: Mat Marcus (mat-lists_at_[hidden])
Date: 2008-09-25 13:06:01

We have a library that depends on boost and is built using
boost-build/jamfiles. In particular our libs require filesystem,
thread, and signal,  but not graph, regex or python. Every time
clients of our library build using boost-build from 1.36.0, they get
the following text at the beginning of the output:

warning: Graph library does not contain optional GraphML reader.
note: to enable GraphML support, set EXPAT_INCLUDE and EXPAT_LIBPATH to the
note: directories containing the Expat headers and libraries, respectively.
warning: skipping optional Message Passing Interface (MPI) library.
note: to enable MPI support, add "using mpi ;" to user-config.jam.
note: to suppress this message, pass "--without-mpi" to bjam.
note: otherwise, you can safely ignore this message.
WARNING: No python installation configured and autoconfiguration
         failed.  See http://www.boost.org/libs/python/doc/building.html
         for configuration instructions or pass --without-python to
         suppress this message and silently skip all Boost.Python targets
Building Boost.Regex with the optional Unicode/ICU support disabled.
Please refer to the Boost.Regex documentation for more information

We have clients in several dozen projects. A number of them have a
warnings-are-errors policy. It is a burden to support them with
respect to these warnings, for several reasons.

1) The clients are not even using the aforementioned libraries.
2) Even if they new the proper incantation, they prefer to type, for
example, "bjam" as opposed to  "bjam --without-mpi --without-python",
etc.
3) --without-mpi no longer seems to suppress the MPI warning in boost
1.36.0. Is --without broken?
4) There doesn't seem to be a documented way to suppress these
warnings from our library's Jamfile.v2

I think it would be a good idea to institute a boost policy like:

Users see no warnings for components that they are not building.

In particular, I'd like to see all of text above vanish when our
library is built. If people don't agree with this, then I'd like to at
least see a way that we could implement this policy from our own
Jamfiles. Thoughts? But for the short term, consider this is a
possible bug report: in our configuration --without-mpi seems to have
no effect. If this isn't just a local issue here, can someone suggest
a workaround and/or a patch?

Thanks,
Mat