From e0fea6c4edcb977d722ed30de4a76a83355e2617 Mon Sep 17 00:00:00 2001
From: Guido van Rossum <guido@python.org>
Date: Mon, 14 Oct 2002 20:48:09 +0000
Subject: [PATCH] [SF bug 620364]

In build_extensions(), don't proceed if srcdir is None.  Probably
somebody who tried this on Windows. :-)
---
 setup.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/setup.py b/setup.py
index 732853483f..7ddef8bd75 100644
--- a/setup.py
+++ b/setup.py
@@ -86,6 +86,9 @@ class PyBuildExt(build_ext):
         # Fix up the autodetected modules, prefixing all the source files
         # with Modules/ and adding Python's include directory to the path.
         (srcdir,) = sysconfig.get_config_vars('srcdir')
+        if not srcdir:
+            # Maybe running on Windows but not using CYGWIN?
+            raise ValueError("No source directory; cannot proceed.")
 
         # Figure out the location of the source code for extension modules
         moddir = os.path.join(os.getcwd(), srcdir, 'Modules')
-- 
2.40.0