Do not reinstall in develop mode without setup.py (#2273)

CONTRIBUTORS

@@ -115,6 +115,7 @@ Tim Laurence
 Tyagraj Desigar
 Usama Sadiq
 Ville Skyttä
+Vincent Vanlaer
 Vlastimil Zíma
 Xander Johnson
 anatoly techtonik

docs/changelog/2197.bugfix.rst

@@ -0,0 +1 @@
+Fixed an issue where ``usedevelop`` would cause an invocation error if setup.py does not exist. -- by :user:`VincentVanlaer`

docs/config.rst

@@ -596,7 +596,9 @@ Complete list of settings that you can put into ``testenv*`` sections:
     Install the current package in development mode with "setup.py
     develop" instead of installing from the ``sdist`` package. (This
     uses pip's ``-e`` option, so should be avoided if you've specified a
-    custom :conf:`install_command` that does not support ``-e``).
+    custom :conf:`install_command` that does not support ``-e``). Note that
+    changes to the build/install process (including changes in dependencies)
+    are only detected when using setuptools with setup.py.
 
 .. conf:: skip_install ^ true|false ^ false
 

src/tox/venv.py

@@ -325,6 +325,10 @@ def finish(self):
 
     def _needs_reinstall(self, setupdir, action):
         setup_py = setupdir.join("setup.py")
+
+        if not setup_py.exists():
+            return False
+
         setup_cfg = setupdir.join("setup.cfg")
         args = [self.envconfig.envpython, str(setup_py), "--name"]
         env = self._get_os_environ()

tests/unit/test_venv.py

@@ -70,6 +70,7 @@ def test_create(mocksession, newconfig):
     assert not venv.path.check()
     with mocksession.newaction(venv.name, "getenv") as action:
         tox_testenv_create(action=action, venv=venv)
+        venv.just_created = True
     pcalls = mocksession._pcalls
     assert len(pcalls) >= 1
     args = pcalls[0].args
@@ -135,6 +136,7 @@ def test_create_sitepackages(mocksession, newconfig):
     venv = mocksession.getvenv("site")
     with mocksession.newaction(venv.name, "getenv") as action:
         tox_testenv_create(action=action, venv=venv)
+        venv.just_created = True
     pcalls = mocksession._pcalls
     assert len(pcalls) >= 1
     args = pcalls[0].args
@@ -144,6 +146,7 @@ def test_create_sitepackages(mocksession, newconfig):
     venv = mocksession.getvenv("nosite")
     with mocksession.newaction(venv.name, "getenv") as action:
         tox_testenv_create(action=action, venv=venv)
+        venv.just_created = True
     pcalls = mocksession._pcalls
     assert len(pcalls) >= 1
     args = pcalls[0].args
@@ -165,6 +168,7 @@ def test_install_deps_wildcard(newmocksession):
     venv = mocksession.getvenv("py123")
     with mocksession.newaction(venv.name, "getenv") as action:
         tox_testenv_create(action=action, venv=venv)
+        venv.just_created = True
         pcalls = mocksession._pcalls
         assert len(pcalls) == 1
         distshare = venv.envconfig.config.distshare
@@ -201,6 +205,7 @@ def test_install_deps_indexserver(newmocksession):
     venv = mocksession.getvenv("py123")
     with mocksession.newaction(venv.name, "getenv") as action:
         tox_testenv_create(action=action, venv=venv)
+        venv.just_created = True
         pcalls = mocksession._pcalls
         assert len(pcalls) == 1
         pcalls[:] = []
@@ -233,6 +238,7 @@ def test_install_deps_pre(newmocksession):
     venv = mocksession.getvenv("python")
     with mocksession.newaction(venv.name, "getenv") as action:
         tox_testenv_create(action=action, venv=venv)
+        venv.just_created = True
     pcalls = mocksession._pcalls
     assert len(pcalls) == 1
     pcalls[:] = []
@@ -294,6 +300,7 @@ def test_install_sdist_extras(newmocksession):
     venv = mocksession.getvenv("python")
     with mocksession.newaction(venv.name, "getenv") as action:
         tox_testenv_create(action=action, venv=venv)
+        venv.just_created = True
     pcalls = mocksession._pcalls
     assert len(pcalls) == 1
     pcalls[:] = []
@@ -314,6 +321,7 @@ def test_develop_extras(newmocksession, tmpdir):
     venv = mocksession.getvenv("python")
     with mocksession.newaction(venv.name, "getenv") as action:
         tox_testenv_create(action=action, venv=venv)
+        venv.just_created = True
     pcalls = mocksession._pcalls
     assert len(pcalls) == 1
     pcalls[:] = []
@@ -519,6 +527,7 @@ def test_install_python3(newmocksession):
     venv = mocksession.getvenv("py123")
     with mocksession.newaction(venv.name, "getenv") as action:
         tox_testenv_create(action=action, venv=venv)
+        venv.just_created = True
         pcalls = mocksession._pcalls
         assert len(pcalls) == 1
         args = pcalls[0].args
@@ -1177,6 +1186,7 @@ def test_create_download(mocksession, newconfig, download):
     venv = mocksession.getvenv("env")
     with mocksession.newaction(venv.name, "getenv") as action:
         tox_testenv_create(action=action, venv=venv)
+        venv.just_created = True
     pcalls = mocksession._pcalls
     assert len(pcalls) >= 1
     args = pcalls[0].args