handle application data folder is read only (#1661)

* fixed FileNotFoundError when directory isn't writable (#1640)

 - when using docker, if `user_data_dir()` isn't writable directory,
   `default_data_dir()` use `system temp directory` + `virtualenv`.
   for example, tempdir is `/tmp`, it use `/tmp/virtualenv`

* start making the app-data more explicit and robust

Signed-off-by: Bernat Gabor <bgabor8@bloomberg.net>

* fix Windows

* fix docs

Signed-off-by: Bernat Gabor <bgabor8@bloomberg.net>

Co-authored-by: Bernát Gábor <gaborjbernat@gmail.com>

4 files changed, 12 insertions, 6 deletions

diff --git a/src/virtualenv/run/plugin/activators.py b/src/virtualenv/run/plugin/activators.py
index 69b3050..dea2827 100644
--- a/src/virtualenv/run/plugin/activators.py
+++ b/src/virtualenv/run/plugin/activators.py
@@ -21,7 +21,7 @@ class ActivationSelector(ComponentBuilder):
         self.parser.add_argument(
             "--{}".format(name),
             default=self.default,
-            metavar="comma_separated_list",
+            metavar="comma_sep_list",
             required=False,
             help="activators to generate - default is all supported",
             type=self._extract_activators,
diff --git a/src/virtualenv/run/plugin/base.py b/src/virtualenv/run/plugin/base.py
index 8aa4206..ed10fe0 100644
--- a/src/virtualenv/run/plugin/base.py
+++ b/src/virtualenv/run/plugin/base.py
@@ -47,12 +47,12 @@ class ComponentBuilder(PluginLoader):
         if selected not in self.possible:
             raise RuntimeError("No implementation for {}".format(self.interpreter))
         self._impl_class = self.possible[selected]
-        self.populate_selected_argparse(selected)
+        self.populate_selected_argparse(selected, options.app_data)
         return selected
 
-    def populate_selected_argparse(self, selected):
+    def populate_selected_argparse(self, selected, app_data):
         self.parser.description = "options for {} {}".format(self.name, selected)
-        self._impl_class.add_parser_arguments(self.parser, self.interpreter)
+        self._impl_class.add_parser_arguments(self.parser, self.interpreter, app_data)
 
     def create(self, options):
         return self._impl_class(options, self.interpreter)
diff --git a/src/virtualenv/run/plugin/creators.py b/src/virtualenv/run/plugin/creators.py
index 7c8132d..cbf0a5d 100644
--- a/src/virtualenv/run/plugin/creators.py
+++ b/src/virtualenv/run/plugin/creators.py
@@ -55,9 +55,9 @@ class CreatorSelector(ComponentBuilder):
     def _get_default(choices):
         return next(iter(choices))
 
-    def populate_selected_argparse(self, selected):
+    def populate_selected_argparse(self, selected, app_data):
         self.parser.description = "options for {} {}".format(self.name, selected)
-        self._impl_class.add_parser_arguments(self.parser, self.interpreter, self.key_to_meta[selected])
+        self._impl_class.add_parser_arguments(self.parser, self.interpreter, self.key_to_meta[selected], app_data)
 
     def create(self, options):
         options.meta = self.key_to_meta[getattr(options, self.name)]
diff --git a/src/virtualenv/run/plugin/discovery.py b/src/virtualenv/run/plugin/discovery.py
index 8890150..43d5eb2 100644
--- a/src/virtualenv/run/plugin/discovery.py
+++ b/src/virtualenv/run/plugin/discovery.py
@@ -1,5 +1,7 @@
 from __future__ import absolute_import, unicode_literals
 
+from virtualenv.run.app_data import TempAppData
+
 from .base import PluginLoader
 
 
@@ -20,6 +22,10 @@ def get_discover(parser, args, options):
         help="interpreter discovery method",
     )
     options, _ = parser.parse_known_args(args, namespace=options)
+    if options.app_data == "<temp folder>":
+        options.app_data = TempAppData()
+    if options.clear_app_data:
+        options.app_data.clean()
     discover_class = discover_types[options.discovery]
     discover_class.add_parser_arguments(discovery_parser)
     options, _ = parser.parse_known_args(args, namespace=options)