On 23.11.2017 21:48, Steven Watanabe via Boost-build wrote:
AMDG

On 11/23/2017 07:26 PM, Stefan Seefeld via Boost-build wrote:
Is there a way for the Jamfile to add a "using zlib ;" or similar that will 
serve as a default, i.e. whenever the user-config.jam file doesn't contain a 
"using zlib " statement ? I'd like to be able to write a valid Jamfile that 
works (and finds prerequisite libs in default locations) without a 
user-config.jam, but allow users to override the paths. But right now it seems I 
have to add "using zlib ;" to either my user-config.jam, or the Jamfile, but not 
both.

They're not exclusive.  It's designed so that

  using zlib ;

with no arguments will work correctly in a Jamfile.
As long as none of <source>, <search>, <name>, or
<include> are specified, `using zlib`, will be ignored,
if a previous `using zlib` already exists.

That sounds sensible indeed, but unfortunately doesn't correspond to my observations. A recent PR build results in

error: at libs\gil\io\test\Jamfile:14
error: libjpeg is already configured
(the full output from AppVeyor is here: https://ci.appveyor.com/project/stefanseefeld/gil/build/job/bb645sw469pbk7ta)

corresponding to this PR: https://github.com/boostorg/gil/commit/fc9e7e2bcb3c85cfe5d8d0930230c9827bdaa8e3

Notice the lines changes to the Jamefile in question ("using libjpeg ;"), in addition to a generated ~/user-config.jam file
containing the CI-specific paths, in the .appveyor.yml logic.

Can you see anything that I'm doing wrong ?

Thanks,

Stefan
-- 

      ...ich hab' noch einen Koffer in Berlin...