exclude '.tox', '.nox' from being copied during 'pip install .'

docs/html/reference/pip_install.rst

@@ -694,10 +694,21 @@ does not satisfy the ``--require-hashes`` demand that every package have a
 local hash.
 
 
+Local project installs
+++++++++++++++++++++++
+pip supports installing local project in both regular mode and editable mode.
+You can install local projects by specifying the project path to pip::
+
+$ pip install path/to/SomeProject
+
+During regular installation, pip will copy the entire project directory to a temporary location and install from there.
+The exception is that pip will exclude .tox and .nox directories present in the top level of the project from being copied.
+
+
 .. _`editable-installs`:
 
 "Editable" Installs
-+++++++++++++++++++
+~~~~~~~~~~~~~~~~~~~
 
 "Editable" installs are fundamentally `"setuptools develop mode"
 <https://setuptools.readthedocs.io/en/latest/setuptools.html#development-mode>`_

news/6770.bugfix

@@ -0,0 +1 @@
+Skip copying .tox and .nox directories to temporary build directories

src/pip/_internal/download.py

@@ -934,12 +934,23 @@ def unpack_file_url(
     of the link file inside download_dir.
     """
     link_path = url_to_path(link.url_without_fragment)
-
     # If it's a url to a local directory
     if is_dir_url(link):
+
+        def ignore(d, names):
+            # Pulling in those directories can potentially be very slow,
+            # exclude the following directories if they appear in the top
+            # level dir (and only it).
+            # See discussion at https://github.com/pypa/pip/pull/6770
+            return ['.tox', '.nox'] if d == link_path else []
+
         if os.path.isdir(location):
             rmtree(location)
-        shutil.copytree(link_path, location, symlinks=True)
+        shutil.copytree(link_path,
+                        location,
+                        symlinks=True,
+                        ignore=ignore)
+
         if download_dir:
             logger.info('Link is a directory, ignoring download_dir')
         return

tests/unit/test_download.py

@@ -413,6 +413,41 @@ def test_unpack_file_url_thats_a_dir(self, tmpdir, data):
         assert os.path.isdir(os.path.join(self.build_dir, 'fspkg'))
 
 
+@pytest.mark.parametrize('exclude_dir', [
+    '.nox',
+    '.tox'
+])
+def test_unpack_file_url_excludes_expected_dirs(tmpdir, exclude_dir):
+    src_dir = tmpdir / 'src'
+    dst_dir = tmpdir / 'dst'
+    src_included_file = src_dir.joinpath('file.txt')
+    src_excluded_dir = src_dir.joinpath(exclude_dir)
+    src_excluded_file = src_dir.joinpath(exclude_dir, 'file.txt')
+    src_included_dir = src_dir.joinpath('subdir', exclude_dir)
+
+    # set up source directory
+    src_excluded_dir.mkdir(parents=True)
+    src_included_dir.mkdir(parents=True)
+    src_included_file.touch()
+    src_excluded_file.touch()
+
+    dst_included_file = dst_dir.joinpath('file.txt')
+    dst_excluded_dir = dst_dir.joinpath(exclude_dir)
+    dst_excluded_file = dst_dir.joinpath(exclude_dir, 'file.txt')
+    dst_included_dir = dst_dir.joinpath('subdir', exclude_dir)
+
+    src_link = Link(path_to_url(src_dir))
+    unpack_file_url(
+        src_link,
+        dst_dir,
+        download_dir=None
+    )
+    assert not os.path.isdir(dst_excluded_dir)
+    assert not os.path.isfile(dst_excluded_file)
+    assert os.path.isfile(dst_included_file)
+    assert os.path.isdir(dst_included_dir)
+
+
 class TestSafeFileCache:
     """
     The no_perms test are useless on Windows since SafeFileCache uses