message: Das: Remove construction of the empty libelle_das.
  libelle_das was relevant when Das wasn't header only anymore.
  Also, macOS versions of ar doesn't like empty archives.
diff: @@ -4,10 +4,6 @@ import drake
  import copy
  import os
  -lib_static = None
  -lib_dynamic = None
  -library = None
  -
  rule_build = None
  rule_check = None
  rule_install = None
  @@ -26,7 +22,6 @@ def configure(cxx_toolkit,
  global rule_install, rule_build, rule_check, rule_tests
  global config
  - global lib_static, lib_dynamic, library
  ## ----------------- ##
  ## C++ configuration ##
  @@ -53,14 +48,6 @@ def configure(cxx_toolkit,
  'serializer.hh',
  'serializer.hxx',
  )
  - lib_dynamic = \
  - drake.cxx.DynLib('lib/elle_das', sources, cxx_toolkit, local_config)
  - lib_static = \
  - drake.cxx.StaticLib('lib/elle_das', sources, cxx_toolkit, local_config)
  - if cxx_toolkit.os in [drake.os.windows, drake.os.ios, drake.os.android]:
  - library = lib_static
  - else:
  - library = lib_dynamic
  ## ----- ##
  ## Tests ##
  @@ -83,7 +70,7 @@ def configure(cxx_toolkit,
  config_tests = drake.cxx.Config(local_config)
  config_tests.add_local_include_path(elle_tests_path)
  - test_libs = [library, elle.library]
  + test_libs = [elle.library]
  config_tests += boost.config_test(
  static = not boost.prefer_shared or None,
  link = not boost.prefer_shared)
  @@ -92,12 +79,12 @@ def configure(cxx_toolkit,
  link = not boost.prefer_shared)
  if boost.prefer_shared:
  test_libs += list(map(lambda x: drake.copy(x, 'lib', strip_prefix = True),
  - [boost.timer_dynamic, boost.test_dynamic, elle.library]))
  + test_libs + [boost.timer_dynamic, boost.test_dynamic]))
  if cxx_toolkit.os is drake.os.android:
  config_tests.lib('stdc++')
  config_tests.lib('atomic')
  config_tests.lib_path_runtime(
  - drake.Path('../../..') / library.path().dirname()
  + drake.Path('../../..') / test_libs[0].path().dirname()
  )
  for name in tests:
  test = drake.cxx.Executable(
  @@ -121,7 +108,7 @@ def configure(cxx_toolkit,
  'examples/samples/das',
  ]
  config_examples = drake.cxx.Config(local_config)
  - example_libs = [library, elle.library]
  + example_libs = [elle.library]
  for example in examples:
  if cxx_toolkit.os in [drake.os.windows, drake.os.ios, drake.os.android]:
  config_examples += boost.config_date_time(static = True)
  @@ -141,9 +128,6 @@ def configure(cxx_toolkit,
  if prefix is not False:
  rule_install = drake.Rule('install')
  - if cxx_toolkit.os not in [drake.os.windows, drake.os.ios]:
  - rule_install << drake.install(lib_dynamic, prefix)
  - rule_install << drake.install(lib_static, prefix)
  rule_install << drake.install(
  (node for node in sources if isinstance(node, drake.cxx.Header)),
  prefix / 'include' / 'elle' / 'das')
  