From b47da272aa849a79b950425ec7bae3cd1b0f1311 Mon Sep 17 00:00:00 2001
From: Bertil Hatt <bertil.hatt@farfetch.com>
Date: Sat, 27 Oct 2018 12:51:21 +0100
Subject: [PATCH] Set sys.argv[0] to the underlying setup.py in the setuptools
 shim.

---
 news/1890.bugfix                            | 2 ++
 src/pip/_internal/req/req_install.py        | 6 +++---
 src/pip/_internal/utils/setuptools_build.py | 7 ++++++-
 src/pip/_internal/wheel.py                  | 2 +-
 4 files changed, 12 insertions(+), 5 deletions(-)
 create mode 100644 news/1890.bugfix

diff --git a/news/1890.bugfix b/news/1890.bugfix
new file mode 100644
index 00000000000..8f85e1255a2
--- /dev/null
+++ b/news/1890.bugfix
@@ -0,0 +1,2 @@
+Set ``sys.argv[0]`` to the underlying ``setup.py`` when invoking ``setup.py``
+via the setuptools shim so setuptools doesn't think the path is ``-c``.
diff --git a/src/pip/_internal/req/req_install.py b/src/pip/_internal/req/req_install.py
index 5192ab2fd42..59305df02be 100644
--- a/src/pip/_internal/req/req_install.py
+++ b/src/pip/_internal/req/req_install.py
@@ -595,7 +595,7 @@ def run_egg_info(self):
                 'Running setup.py (path:%s) egg_info for package from %s',
                 self.setup_py_path, self.link,
             )
-        script = SETUPTOOLS_SHIM % self.setup_py_path
+        script = SETUPTOOLS_SHIM.format(self.setup_py_path)
         base_cmd = [sys.executable, '-c', script]
         if self.isolated:
             base_cmd += ["--no-user-cfg"]
@@ -757,7 +757,7 @@ def install_editable(
                     [
                         sys.executable,
                         '-c',
-                        SETUPTOOLS_SHIM % self.setup_py_path
+                        SETUPTOOLS_SHIM.format(self.setup_py_path)
                     ] +
                     list(global_options) +
                     ['develop', '--no-deps'] +
@@ -1004,7 +1004,7 @@ def get_install_args(
         # type: (...) -> List[str]
         install_args = [sys.executable, "-u"]
         install_args.append('-c')
-        install_args.append(SETUPTOOLS_SHIM % self.setup_py_path)
+        install_args.append(SETUPTOOLS_SHIM.format(self.setup_py_path))
         install_args += list(global_options) + \
             ['install', '--record', record_filename]
         install_args += ['--single-version-externally-managed']
diff --git a/src/pip/_internal/utils/setuptools_build.py b/src/pip/_internal/utils/setuptools_build.py
index 03973e976ca..207c6fb96da 100644
--- a/src/pip/_internal/utils/setuptools_build.py
+++ b/src/pip/_internal/utils/setuptools_build.py
@@ -1,6 +1,11 @@
 # Shim to wrap setup.py invocation with setuptools
+#
+# We set sys.argv[0] to the path to the underlying setup.py file so
+# setuptools / distutils don't take the path to the setup.py to be "-c" when
+# invoking via the shim.  This avoids e.g. the following manifest_maker
+# warning: "warning: manifest_maker: standard file '-c' not found".
 SETUPTOOLS_SHIM = (
-    "import setuptools, tokenize;__file__=%r;"
+    "import sys, setuptools, tokenize; sys.argv[0] = {0!r}; __file__={0!r};"
     "f=getattr(tokenize, 'open', open)(__file__);"
     "code=f.read().replace('\\r\\n', '\\n');"
     "f.close();"
diff --git a/src/pip/_internal/wheel.py b/src/pip/_internal/wheel.py
index a7350c9eca9..a3934acba24 100644
--- a/src/pip/_internal/wheel.py
+++ b/src/pip/_internal/wheel.py
@@ -930,7 +930,7 @@ def _base_setup_args(self, req):
         # virtualenv.
         return [
             sys.executable, '-u', '-c',
-            SETUPTOOLS_SHIM % req.setup_py_path,
+            SETUPTOOLS_SHIM.format(req.setup_py_path)
         ] + list(self.global_options)
 
     def _build_one_pep517(self, req, tempd, python_tag=None):