remove DistributionNotFound when no version is found

- and rely on if not applicable_versions test instead
- fixes #2502
- rephrase the DistributionNotFound error message to fix other tests

pip/index.py

@@ -421,31 +421,8 @@ def find_requirement(self, req, upgrade):
         Returns an InstallationCandidate or None
         May raise DistributionNotFound or BestVersionAlreadyInstalled"""
         all_versions = self._find_all_versions(req)
-        if not all_versions:
-            logger.critical(
-                'Could not find any downloads that satisfy the requirement %s',
-                req,
-            )
-
-            if self.need_warn_external:
-                logger.warning(
-                    "Some externally hosted files were ignored as access to "
-                    "them may be unreliable (use --allow-external %s to "
-                    "allow).",
-                    req.name,
-                )
-
-            if self.need_warn_unverified:
-                logger.warning(
-                    "Some insecure and unverifiable files were ignored"
-                    " (use --allow-unverified %s to allow).",
-                    req.name,
-                )
-
-            raise DistributionNotFound(
-                'No distributions at all found for %s' % req
-            )
         # Filter out anything which doesn't match our specifier
+
         _versions = set(
             req.specifier.filter(
                 [x.version for x in all_versions],
@@ -507,7 +484,9 @@ def find_requirement(self, req, upgrade):
             if self.need_warn_external:
                 logger.warning(
                     "Some externally hosted files were ignored as access to "
-                    "them may be unreliable (use --allow-external to allow)."
+                    "them may be unreliable (use --allow-external %s to "
+                    "allow).",
+                    req.name,
                 )
 
             if self.need_warn_unverified:
@@ -518,7 +497,7 @@ def find_requirement(self, req, upgrade):
                 )
 
             raise DistributionNotFound(
-                'No distributions matching the version for %s' % req
+                'No matching distribution found for %s' % req
             )
 
         if applicable_versions[0].location is INSTALLED_VERSION:

tests/functional/test_install.py

@@ -739,3 +739,28 @@ def test_no_compiles_pyc(script, data):
     )
 
     assert not any(exists)
+
+
+def test_install_upgrade_editable_depending_on_other_editable(script):
+    script.scratch_path.join("pkga").mkdir()
+    pkga_path = script.scratch_path / 'pkga'
+    pkga_path.join("setup.py").write(textwrap.dedent("""
+        from setuptools import setup
+        setup(name='pkga',
+              version='0.1')
+    """))
+    script.pip('install', '--editable', pkga_path)
+    result = script.pip('list')
+    assert "pkga" in result.stdout
+
+    script.scratch_path.join("pkgb").mkdir()
+    pkgb_path = script.scratch_path / 'pkgb'
+    pkgb_path.join("setup.py").write(textwrap.dedent("""
+        from setuptools import setup
+        setup(name='pkgb',
+              version='0.1',
+              install_requires=['pkga'])
+    """))
+    script.pip('install', '--upgrade', '--editable', pkgb_path)
+    result = script.pip('list')
+    assert "pkgb" in result.stdout

tests/functional/test_install_config.py

@@ -13,7 +13,7 @@ def test_options_from_env_vars(script):
     result = script.pip('install', '-vvv', 'INITools', expect_error=True)
     assert "Ignoring indexes:" in result.stdout, str(result)
     assert (
-        "DistributionNotFound: No distributions at all found for INITools"
+        "DistributionNotFound: No matching distribution found for INITools"
         in result.stdout
     )
 
@@ -68,7 +68,7 @@ def _test_env_vars_override_config_file(script, virtualenv, config_file):
         """))
     result = script.pip('install', '-vvv', 'INITools', expect_error=True)
     assert (
-        "DistributionNotFound: No distributions at all found for INITools"
+        "DistributionNotFound: No matching distribution found for INITools"
         in result.stdout
     )
     script.environ['PIP_NO_INDEX'] = '0'
@@ -184,6 +184,6 @@ def test_options_from_venv_config(script, virtualenv):
     result = script.pip('install', '-vvv', 'INITools', expect_error=True)
     assert "Ignoring indexes:" in result.stdout, str(result)
     assert (
-        "DistributionNotFound: No distributions at all found for INITools"
+        "DistributionNotFound: No matching distribution found for INITools"
         in result.stdout
     )