Wrap usage of get_makefile_filename

Per the issue mentioned inline, this function may have different
names.  Probe for the _ prefixed version as well.

Closes: pypa#1810

src/virtualenv/create/debug.py

@@ -55,7 +55,14 @@ def run():
     try:
         import sysconfig
 
-        result["makefile_filename"] = encode_path(sysconfig.get_makefile_filename())
+        try:
+            get_makefile_filename = sysconfig.get_makefile_filename
+        except AttributeError:
+            # On some platforms, get_makefile_filename doesn't exist
+            #  https://bugs.python.org/issue22199
+            get_makefile_filename = sysconfig._get_makefile_filename
+
+        result["makefile_filename"] = encode_path(get_makefile_filename())
     except ImportError:
         pass
 

src/virtualenv/discovery/py_info.py

@@ -24,6 +24,14 @@ def _get_path_extensions():
     return list(OrderedDict.fromkeys([""] + os.environ.get("PATHEXT", "").lower().split(os.pathsep)))
 
 
+try:
+    get_makefile_filename = sysconfig.get_makefile_filename
+except AttributeError:
+    # On some platforms, get_makefile_filename doesn't exist
+    #  https://bugs.python.org/issue22199
+    get_makefile_filename = sysconfig._get_makefile_filename
+
+
 EXTENSIONS = _get_path_extensions()
 _CONF_VAR_RE = re.compile(r"\{\w+\}")
 
@@ -78,9 +86,7 @@ def abs_path(v):
 
         self.sysconfig = {
             u(k): u(v)
-            for k, v in [  # a list of content to store from sysconfig
-                ("makefile_filename", sysconfig.get_makefile_filename()),
-            ]
+            for k, v in [("makefile_filename", get_makefile_filename()),]  # a list of content to store from sysconfig
             if k is not None
         }