1 files changed, 54 insertions, 30 deletions

diff --git a/pavement.py b/pavement.py
index 1ef6a2a5..f255dc9b 100644
--- a/pavement.py
+++ b/pavement.py
@@ -1,17 +1,21 @@
 import re
 from textwrap import dedent
 
+import sys
+
 from paver.easy import task, path as Path
 import pip
 
 
+del sys.path[0]
+
+
 def remove_all(paths):
     for path in paths:
         path.rmtree() if path.isdir() else path.remove()
 
 
-def patch_pkg_resources(vendor):
-    pkg_resources = vendor / 'pkg_resources'
+def rewrite_pkg_resources(pkg_resources, new_root):
     for file in pkg_resources.glob('__init__.py'):
         text = file.text()
         text = text.replace(dedent("""
@@ -20,51 +24,71 @@ def patch_pkg_resources(vendor):
             import packaging.specifiers
             import packaging.requirements
             import packaging.markers
-            """), dedent("""
-            from setuptools.extern import appdirs
-            from setuptools.extern import packaging
-            __import__('setuptools.extern.packaging.version')
-            __import__('setuptools.extern.packaging.specifiers')
-            __import__('setuptools.extern.packaging.requirements')
-            __import__('setuptools.extern.packaging.markers')
+            """), dedent(f"""
+            from {new_root} import appdirs
+            from {new_root} import packaging
+            __import__('{new_root}.packaging.version')
+            __import__('{new_root}.packaging.specifiers')
+            __import__('{new_root}.packaging.requirements')
+            __import__('{new_root}.packaging.markers')
             """),
         )
         text = text.replace(dedent("""
             import six
             from six.moves import urllib, map, filter
-            """), dedent("""
-            from setuptools.extern import six
-            from setuptools.extern.six import urllib, map, filter
+            """), dedent(f"""
+            from {new_root} import six
+            from {new_root}.six import urllib, map, filter
             """),
         )
         file.write_text(text)
-    remove_all(vendor.glob('setuptools/_vendor/pkg_resources/_vendor'))
-    remove_all(vendor.glob('setuptools/_vendor/pkg_resources/extern'))
-    remove_all(vendor.glob('setuptools/_vendor/pkg_resources/tests'))
+    remove_all(pkg_resources.glob('_vendor'))
+    remove_all(pkg_resources.glob('extern'))
+    remove_all(pkg_resources.glob('tests'))
 
 
 @task
 def update_vendored():
-    vendor = Path('setuptools/_vendor')
-    # pip uninstall doesn't support -t, so do it manually
-    remove_all(vendor.glob('packaging*'))
-    remove_all(vendor.glob('six*'))
-    remove_all(vendor.glob('pyparsing*'))
-    remove_all(vendor.glob('appdirs*'))
-    remove_all(vendor.glob('pkg_resources*'))
+    update_setuptools()
+
+
+def rewrite_packaging(pkg_files, new_root):
+    """
+    Rewrite imports in packaging to redirect to vendored copies.
+    """
+    for file in pkg_files.glob('*.py'):
+        text = file.text()
+        text = re.sub(r' (pyparsing|six)', rf' {new_root}.\1', text)
+        file.write_text(text)
+
+
+def clean(vendor):
+    """
+    Remove all files out of the vendor directory except the meta
+    data (as pip uninstall doesn't support -t).
+    """
+    remove_all(
+        path
+        for path in vendor.glob('*')
+        if path.basename() != 'vendored.txt'
+    )
+
+
+def install(vendor):
+    clean(vendor)
     install_args = [
         'install',
         '-r', str(vendor / 'vendored.txt'),
         '-t', str(vendor),
     ]
     pip.main(install_args)
-    packaging = vendor / 'packaging'
-    for file in packaging.glob('*.py'):
-        text = file.text()
-        text = re.sub(r' (pyparsing|six)', r' setuptools.extern.\1', text)
-        file.write_text(text)
-
-    patch_pkg_resources(vendor)
-
     remove_all(vendor.glob('*.dist-info'))
     remove_all(vendor.glob('*.egg-info'))
+    (vendor / '__init__.py').write_text('')
+
+
+def update_setuptools():
+    vendor = Path('setuptools/_vendor')
+    install(vendor)
+    rewrite_packaging(vendor / 'packaging', 'setuptools.extern')
+    rewrite_pkg_resources(vendor / 'pkg_resources', 'setuptools.extern')