Fixed result of tox_get_python_executable not being used to make virtualenvs (#1301)

* Fixed result of tox_get_python_executable not being used to make virtualenvs

* fix formatting and add changelog

5 files changed, 35 insertions, 0 deletions

diff --git a/CONTRIBUTORS b/CONTRIBUTORS
index e3301f9f..fcd11b18 100644
--- a/CONTRIBUTORS
+++ b/CONTRIBUTORS
@@ -6,6 +6,7 @@ Allan Feldman
 Andrii Soldatenko
 Anthon van der Neuth
 Anthony Sottile
+Ashley Whetter
 Asmund Grammeltwedt
 Barry Warsaw
 Bartolome Sanchez Salado
diff --git a/docs/changelog/1301.bugfix.rst b/docs/changelog/1301.bugfix.rst
new file mode 100644
index 00000000..c666827f
--- /dev/null
+++ b/docs/changelog/1301.bugfix.rst
@@ -0,0 +1 @@
+When creating virtual environments we no longer ask the python to tell its path, but rather use the discovered path.
diff --git a/src/tox/interpreters.py b/src/tox/interpreters.py
index 23be42d6..14f9eb42 100644
--- a/src/tox/interpreters.py
+++ b/src/tox/interpreters.py
@@ -67,6 +67,7 @@ def run_and_get_interpreter_info(name, executable):
         result["version_info"] = tuple(result["version_info"])  # fix json dump transformation
         del result["name"]
         del result["version"]
+        result["executable"] = str(executable)
     except ExecFailed as e:
         return NoInterpreterInfo(name, executable=e.executable, out=e.out, err=e.err)
     else:
diff --git a/src/tox/logs/env.py b/src/tox/logs/env.py
index bbdc0be5..f134440a 100644
--- a/src/tox/logs/env.py
+++ b/src/tox/logs/env.py
@@ -20,6 +20,7 @@ class EnvLog(object):
         cmd = [str(python_executable), VERSION_QUERY_SCRIPT]
         result = subprocess.check_output(cmd, universal_newlines=True)
         answer = json.loads(result)
+        answer["executable"] = python_executable
         self.dict["python"] = answer
 
     def get_commandlog(self, name):
diff --git a/tests/unit/test_interpreters.py b/tests/unit/test_interpreters.py
index 1eba27eb..e7928cf7 100644
--- a/tests/unit/test_interpreters.py
+++ b/tests/unit/test_interpreters.py
@@ -1,4 +1,7 @@
+from __future__ import unicode_literals
+
 import os
+import stat
 import subprocess
 import sys
 
@@ -137,6 +140,34 @@ class TestInterpreters:
         assert not info.executable
         assert isinstance(info, NoInterpreterInfo)
 
+    @pytest.mark.skipif("sys.platform == 'win32'", reason="Uses a unix only wrapper")
+    def test_get_info_uses_hook_path(self, tmp_path):
+        magic = tmp_path / "magic{}".format(os.path.splitext(sys.executable)[1])
+        wrapper = (
+            "#!{executable}\n"
+            "import subprocess\n"
+            "import sys\n"
+            'sys.exit(subprocess.call(["{executable}"] + sys.argv[1:]))\n'
+        ).format(executable=sys.executable)
+        magic.write_text(wrapper)
+        magic.chmod(magic.stat().st_mode | stat.S_IEXEC)
+
+        class MockHook:
+            def tox_get_python_executable(self, envconfig):
+                return str(magic)
+
+        class envconfig:
+            basepython = sys.executable
+            envname = "magicpy"
+
+        # Check that the wrapper is working first.
+        # If it isn't, the default is to return the passed path anyway.
+        subprocess.check_call([str(magic), "--help"])
+
+        interpreters = Interpreters(hook=MockHook())
+        info = interpreters.get_info(envconfig)
+        assert info.executable == str(magic)
+
     def test_get_sitepackagesdir_error(self, interpreters):
         class envconfig:
             basepython = sys.executable