fix compatibility with older versions of setuptools

Author: fafhrd91

.gitignore

@@ -5,5 +5,7 @@
 /build
 /*.egg-info
 Cargo.lock
+/example/build/
+/example/dist/
 /example/extensions/target/
 /example/*.egg-info

CHANGES.rst

@@ -1,9 +1,10 @@
 CHANGES
 =======
 
-0.4 (2017-xx-xx)
-----------------
+0.3.1 (2017-03-09)
+------------------
 
+- Fix compatibility with some old versions of setuptools
 
 
 0.3 (2017-03-09)

setup.py

@@ -1,6 +1,6 @@
 from setuptools import setup
 
-version = '0.4'
+version = '0.3.1'
 
 
 setup(

setuptools_rust/patch.py

@@ -13,6 +13,8 @@
 Distribution.rust_extensions = ()
 
 
+orig_has_ext_modules = Distribution.has_ext_modules
+
 def has_ext_modules(self):
     return (self.ext_modules and len(self.ext_modules) > 0 or
             self.rust_extensions and len(self.rust_extensions) > 0)
@@ -45,14 +47,46 @@ def monkey_run_command(self, cmd):
 develop.develop.run_command = monkey_run_command
 
 
-# monkey patch "sdist_add_defaults"
-
-def _add_defaults_ext(self):
-    if (self.distribution.ext_modules and
-            len(self.distribution.ext_modules) > 0):
-        build_ext = self.get_finalized_command('build_ext')
-        self.filelist.extend(build_ext.get_source_files())
+if has_py36compat:
+    # monkey patch "sdist_add_defaults"
 
+    def _add_defaults_ext(self):
+        if (self.distribution.ext_modules and
+                len(self.distribution.ext_modules) > 0):
+            build_ext = self.get_finalized_command('build_ext')
+            self.filelist.extend(build_ext.get_source_files())
 
-if has_py36compat:
     sdist_add_defaults._add_defaults_ext = _add_defaults_ext
+else:
+    from distutils.command.build_ext import build_ext
+    from setuptools.command.bdist_egg import bdist_egg
+
+    orig_get_source_files = build_ext.get_source_files
+
+    def get_source_files(self):
+        if self.extensions:
+            return orig_get_source_files(self)
+        else:
+            return []
+
+    build_ext.get_source_files = get_source_files
+
+    orig_get_ext_outputs = bdist_egg.get_ext_outputs
+
+    def get_ext_outputs(self):
+        Distribution.has_ext_modules = orig_has_ext_modules
+        try:
+            return orig_get_ext_outputs(self)
+        finally:
+            Distribution.has_ext_modules = has_ext_modules
+
+
+    bdist_egg.get_ext_outputs = get_ext_outputs
+
+    orig_run = bdist_egg.run
+
+    def run(self):
+        self.run_command("build_rust")
+        orig_run(self)
+
+    bdist_egg.run = run