Allow install to proceed with an egg install on IronPython and any other...

Allow install to proceed with an egg install on IronPython and any other environment that has no stack support. Fixes #177.

CHANGES.txt

@@ -8,6 +8,10 @@ CHANGES
 
 * Issue #176: Add parameter to the test command to support a custom test
   runner: --test-runner or -r.
+* Issue #177: Now assume most common invocation to install command on
+  platforms/environments without stack support (issuing a warning). Setuptools
+  now installs naturally on IronPython. Behavior on CPython should be
+  unchanged.
 
 ---
 3.3

setuptools/command/install.py

 import setuptools
 import inspect
 import glob
+import warnings
+import platform
 from distutils.command.install import install as _install
 from distutils.errors import DistutilsArgError
 
@@ -66,8 +68,16 @@ class install(_install):
         'run_command' method in 'distutils.dist', and *its* caller will be
         the 'run_commands' method.  If called any other way, the
         immediate caller *might* be 'run_command', but it won't have been
-        called by 'run_commands'. Return True in that case or False otherwise.
+        called by 'run_commands'. Return True in that case or if a call stack
+        is unavailable. Return False otherwise.
         """
+        if run_frame is None:
+            msg = "Call stack not available. bdist_* commands may fail."
+            warnings.warn(msg)
+            if platform.python_implementation() == 'IronPython':
+                msg = "For best results, pass -X:Frames to enable call stack."
+                warnings.warn(msg)
+            return True
         res = inspect.getouterframes(run_frame)[2]
         caller, = res[:1]
         info = inspect.getframeinfo(caller)