On 23.11.2017 22:25, Steven Watanabe via Boost-build wrote:
AMDG

On 11/23/2017 08:09 PM, Steven Watanabe wrote:
On 11/23/2017 07:57 PM, Stefan Seefeld via Boost-build wrote:
On 23.11.2017 21:48, Steven Watanabe via Boost-build wrote:
   using zlib ;

with no arguments will work correctly in a Jamfile.
<snip>
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)

<snip>

Can you see anything that I'm doing wrong ?

  Nope.  This is a bug.

You can make it work with

using libjpeg
  : # version
  : # options
  : # requirements
  : # is-default
    true
  ;

(The options are described by `b2 --help libjpeg.init`)

I'll update libjpeg to match zlib, which decides
automatically whether it should be a default configuration.

Thank you ! (I'm also using libpng and libtiff, so it's possible that these exhibit the same problem. We shall find out soon enough.)

Stefan
-- 

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