We need EV_COMMON for the CFFI embedded case.

.travis.yml

@@ -141,7 +141,7 @@ jobs:
         # libev builds a manpage each time, and it includes today's date, so it frequently changes.
         # delete to avoid repacking the archive
         - rm -rf $BUILD_LIBS/share/man/
-        - ls -l $BUILD_LIBS $BUILD_LIBS/lib
+        - ls -l $BUILD_LIBS $BUILD_LIBS/lib $BUILD_LIBS/include
         - pip install --no-build-isolation .[test]
         - objdump -p src/gevent/libev/*so
       script:

_setuplibev.py

@@ -85,7 +85,9 @@ def build_extension():
 
     if LIBEV_EMBED:
         CORE.define_macros += [('LIBEV_EMBED', '1'),
-                               ('EV_COMMON', ''),  # we don't use void* data
+                               # we don't use void* data in the cython implementation;
+                               # the CFFI implementation does and removes this line.
+                               ('EV_COMMON', ''),
                                # libev watchers that we don't use currently:
                                ('EV_CLEANUP_ENABLE', '0'),
                                ('EV_EMBED_ENABLE', '0'),

src/gevent/libev/_corecffi_build.py

@@ -70,12 +70,19 @@ _source = read_source('_corecffi_source.c')
 
 distutils_ext = _setuplibev.build_extension()
 
+macros = list(distutils_ext.define_macros)
+try:
+    # We need the data pointer.
+    macros.remove(('EV_COMMON', ''))
+except ValueError:
+    pass
+
 ffi.cdef(_cdef)
 ffi.set_source(
     'gevent.libev._corecffi',
     _source,
-    include_dirs=distutils_ext.include_dirs,
-    define_macros=distutils_ext.define_macros,
+    include_dirs=distutils_ext.include_dirs + [thisdir], # "libev.h"
+    define_macros=macros,
     libraries=distutils_ext.libraries,
 )