Merge pull request #4999 from xoviat/pep518-editable

Run setup.py develop inside of PEP 518 build environment

news/4999.feature

@@ -0,0 +1 @@
+Run 'setup.py develop' inside pep518 build environment.

src/pip/_internal/req/req_install.py

@@ -897,19 +897,20 @@ class InstallRequirement(object):
 
         with indent_log():
             # FIXME: should we do --install-headers here too?
-            call_subprocess(
-                [
-                    sys.executable,
-                    '-c',
-                    SETUPTOOLS_SHIM % self.setup_py
-                ] +
-                list(global_options) +
-                ['develop', '--no-deps'] +
-                list(install_options),
+            with self.build_env:
+                call_subprocess(
+                    [
+                        sys.executable,
+                        '-c',
+                        SETUPTOOLS_SHIM % self.setup_py
+                    ] +
+                    list(global_options) +
+                    ['develop', '--no-deps'] +
+                    list(install_options),
 
-                cwd=self.setup_py_dir,
-                show_stdout=False,
-            )
+                    cwd=self.setup_py_dir,
+                    show_stdout=False,
+                )
 
         self.install_succeeded = True
 

tests/functional/test_install_reqs.py

@@ -300,6 +300,14 @@ def test_constraints_local_editable_install_causes_error(script, data):
     assert 'Could not satisfy constraints for' in result.stderr
 
 
+def test_constraints_local_editable_install_pep518(script, data):
+    to_install = data.src.join("pep518-3.0")
+
+    script.pip('download', 'setuptools', 'wheel', '-d', data.packages)
+    script.pip(
+        'install', '--no-index', '-f', data.find_links, '-e', to_install)
+
+
 def test_constraints_local_install_causes_error(script, data):
     script.scratch_path.join("constraints.txt").write(
         "singlemodule==0.0.0"