updated config file name for Python 3.6 (#2881)

var/spack/repos/builtin/packages/python/package.py

@@ -148,6 +148,16 @@ def install(self, spec, prefix):
         make()
         make('install')
 
+        self.sysconfigfilename = '_sysconfigdata.py'
+        if spec.satisfies('@3.6:'):
+            # Python 3.6.0 renamed the sys config file
+            python3 = os.path.join(prefix.bin,
+                                   'python{0}'.format(self.version.up_to(1)))
+            python = Executable(python3)
+            sc = 'import sysconfig; print(sysconfig._get_sysconfigdata_name())'
+            cf = python('-c', sc, output=str).strip('\n')
+            self.sysconfigfilename = '{0}.py'.format(cf)
+
         self._save_distutil_vars(prefix)
 
         self.filter_compilers(prefix)
@@ -207,12 +217,11 @@ def _save_distutil_vars(self, prefix):
         input_filename = None
         for filename in [join_path(lib_dir,
                                    'python{0}'.format(self.version.up_to(2)),
-                                   '_sysconfigdata.py')
+                                   self.sysconfigfilename)
                          for lib_dir in [prefix.lib, prefix.lib64]]:
             if os.path.isfile(filename):
                 input_filename = filename
                 break
-
         if not input_filename:
             return
 
@@ -301,7 +310,7 @@ def filter_compilers(self, prefix):
         config_dirname = 'config-{0}m'.format(
             self.version.up_to(2)) if self.spec.satisfies('@3:') else 'config'
 
-        rel_filenames = ['_sysconfigdata.py',
+        rel_filenames = [self.sysconfigfilename,
                          join_path(config_dirname, 'Makefile')]
 
         abs_filenames = [join_path(dirname, filename) for dirname in