Backport PR #2068: record sysinfo in sdist

closes  #2054

setup.py

@@ -52,7 +52,6 b' from glob import glob'
 if os.path.exists('MANIFEST'): os.remove('MANIFEST')
 
 from distutils.core import setup
-from distutils.command.upload import upload
 
 # On Python 3, we need distribute (new setuptools) to do the 2to3 conversion
 if PY3:
@@ -166,14 +165,16 b' packages = find_packages()'
 package_data = find_package_data()
 data_files = find_data_files()
 
-setup_args['cmdclass'] = {'build_py': record_commit_info('IPython')}
 setup_args['packages'] = packages
 setup_args['package_data'] = package_data
 setup_args['data_files'] = data_files
 
 #---------------------------------------------------------------------------
-# custom upload_wininst command
+# custom distutils commands
 #---------------------------------------------------------------------------
+# imports here, so they are after setuptools import if there was one
+from distutils.command.sdist import sdist
+from distutils.command.upload import upload
 
 class UploadWindowsInstallers(upload):
 
@@ -194,7 +195,11 b' class UploadWindowsInstallers(upload):'
         for dist_file in glob(self.files):
             self.upload_file('bdist_wininst', 'any', dist_file)
 
-setup_args['cmdclass']['upload_wininst'] = UploadWindowsInstallers
+setup_args['cmdclass'] = {
+    'build_py': record_commit_info('IPython'),
+    'sdist' : record_commit_info('IPython', sdist),
+    'upload_wininst' : UploadWindowsInstallers,
+}
 
 #---------------------------------------------------------------------------
 # Handle scripts, dependencies, and setuptools specific things

setupbase.py

@@ -369,7 +369,7 b' def check_for_dependencies():'
     check_for_readline()
 
 def record_commit_info(pkg_dir, build_cmd=build_py):
-    """ Return extended build command class for recording commit
+    """ Return extended build or sdist command class for recording commit
     
     records git commit in IPython.utils._sysinfo.commit
     
@@ -380,18 +380,40 b' def record_commit_info(pkg_dir, build_cmd=build_py):'
         ''' Subclass to write commit data into installation tree '''
         def run(self):
             build_cmd.run(self)
+            # this one will only fire for build commands
+            if hasattr(self, 'build_lib'):
+                self._record_commit(self.build_lib)
+
+        def make_release_tree(self, base_dir, files):
+            # this one will fire for sdist
+            build_cmd.make_release_tree(self, base_dir, files)
+            self._record_commit(base_dir)
+
+        def _record_commit(self, base_dir):
             import subprocess
             proc = subprocess.Popen('git rev-parse --short HEAD',
                                     stdout=subprocess.PIPE,
                                     stderr=subprocess.PIPE,
                                     shell=True)
             repo_commit, _ = proc.communicate()
-            repo_commit = repo_commit.strip()
-            # We write the installation commit even if it's empty
-            out_pth = pjoin(self.build_lib, pkg_dir, 'utils', '_sysinfo.py')
+            repo_commit = repo_commit.strip().decode("ascii")
+
+            out_pth = pjoin(base_dir, pkg_dir, 'utils', '_sysinfo.py')
+            if os.path.isfile(out_pth) and not repo_commit:
+                # nothing to write, don't clobber
+                return
+
+            print("writing git commit '%s' to %s" % (repo_commit, out_pth))
+
+            # remove to avoid overwriting original via hard link
+            try:
+                os.remove(out_pth)
+            except (IOError, OSError):
+                pass
+            print (out_pth, file=sys.stderr)
             with open(out_pth, 'w') as out_file:
                 out_file.writelines([
                     '# GENERATED BY setup.py\n',
-                    'commit = "%s"\n' % repo_commit.decode('ascii'),
+                    'commit = "%s"\n' % repo_commit,
                 ])
     return MyBuildPy