ares is not optional on travis; more debugging

Makefile

@@ -163,7 +163,8 @@ develop:
 # Then start installing our deps so they can be cached. Note that use of --build-options / --global-options / --install-options
 # disables the cache.
 # We need wheel>=0.26 on Python 3.5. See previous revisions.
-	${PIP} install -vv -U -r dev-requirements.txt
+	${PIP} install -v -U -r dev-requirements.txt
+	cat deps/c-ares/ares_build.h
 
 lint-py27: $(PY27)
 	PYTHON=python2.7.13 PATH=$(BUILD_RUNTIMES)/versions/python2.7.13/bin:$(PATH) make develop travis_test_linters

_setupares.py

@@ -23,6 +23,7 @@ from _setuputils import LIBRARIES
 from _setuputils import DEFINE_MACROS
 from _setuputils import glob_many
 from _setuputils import dep_abspath
+from _setuputils import RUNNING_ON_TRAVIS
 
 
 CARES_EMBED = should_embed('c-ares')
@@ -83,7 +84,8 @@ ARES = Extension(name='gevent.ares',
                  define_macros=list(DEFINE_MACROS),
                  depends=glob_many('src/gevent/dnshelper.c',
                                    'src/gevent/cares_*.[ch]'))
-ARES.optional = True
+
+ARES.optional = not RUNNING_ON_TRAVIS
 
 
 if CARES_EMBED:

_setuputils.py

@@ -22,6 +22,7 @@ from setuptools.command.sdist import sdist
 PYPY = hasattr(sys, 'pypy_version_info')
 WIN = sys.platform.startswith('win')
 CFFI_WIN_BUILD_ANYWAY = os.environ.get("PYPY_WIN_BUILD_ANYWAY")
+RUNNING_ON_TRAVIS = os.environ.get('TRAVIS')
 
 LIBRARIES = []
 DEFINE_MACROS = []

setup.py

@@ -187,7 +187,7 @@ if os.getenv('READTHEDOCS'):
 try:
     run_setup(EXT_MODULES, run_make=_BUILDING)
 except BuildFailed:
-    if ARES not in EXT_MODULES:
+    if ARES not in EXT_MODULES or not ARES.optional:
         raise
     EXT_MODULES.remove(ARES)
     run_setup(EXT_MODULES, run_make=_BUILDING)