Fixes for Py3.8 compatibility.

docs/reference/commands/index.rst

@@ -27,11 +27,14 @@ Override the value of an app's configuration in ``pyproject.toml`` with the prov
 value.
 
 The value passed to the setting should be valid TOML. If the value being overridden is a
-string, this includes quoting the value. This may require the use of escape sequences at
-the command line. For example, to override the template used by the create command, you
-can use ``-C template=...``, but the value must be quoted::
+string, this means you must quote the value. This may require the use of escape
+sequences at the command line to ensure the value provided to Briefcase by the shell
+includes the quotes.
 
-    briefcase create -C template=\'https://example.com/template\'
+For example, to override the template used by the create command, you can use ``-C
+template=...``, but the value must be quoted::
+
+    briefcase create -C template=\"https://example.com/template\"
 
 ``-h`` / ``--help``
 -------------------

src/briefcase/commands/dev.py

@@ -1,8 +1,9 @@
+from __future__ import annotations
+
 import os
 import subprocess
 import sys
 from pathlib import Path
-from typing import List, Optional
 
 from briefcase.commands.run import RunAppMixin
 from briefcase.config import AppConfig
@@ -112,7 +113,7 @@ def run_dev_app(
         app: AppConfig,
         env: dict,
         test_mode: bool,
-        passthrough: List[str],
+        passthrough: list[str],
         **options,
     ):
         """Run the app in the dev environment.
@@ -174,11 +175,11 @@ def get_environment(self, app, test_mode: bool):
 
     def __call__(
         self,
-        appname: Optional[str] = None,
-        update_requirements: Optional[bool] = False,
-        run_app: Optional[bool] = True,
-        test_mode: Optional[bool] = False,
-        passthrough: Optional[List[str]] = None,
+        appname: str | None = None,
+        update_requirements: bool | None = False,
+        run_app: bool | None = True,
+        test_mode: bool | None = False,
+        passthrough: list[str] | None = None,
         config_overrides: list[str] | None = None,
         **options,
     ):

src/briefcase/commands/new.py

@@ -1,7 +1,8 @@
+from __future__ import annotations
+
 import re
 import unicodedata
 from email.utils import parseaddr
-from typing import Optional
 from urllib.parse import urlparse
 
 from packaging.version import Version
@@ -432,8 +433,8 @@ def build_app_context(self):
 
     def new_app(
         self,
-        template: Optional[str] = None,
-        template_branch: Optional[str] = None,
+        template: str | None = None,
+        template_branch: str | None = None,
         **options,
     ):
         """Ask questions to generate a new application, and generate a stub project from
@@ -520,8 +521,8 @@ def verify_tools(self):
 
     def __call__(
         self,
-        template: Optional[str] = None,
-        template_branch: Optional[str] = None,
+        template: str | None = None,
+        template_branch: str | None = None,
         **options,
     ):
         # Confirm host compatibility, and that all required tools are available.

src/briefcase/commands/upgrade.py

@@ -1,6 +1,7 @@
+from __future__ import annotations
+
 import sys
 from operator import attrgetter
-from typing import List, Set, Type
 
 from briefcase.exceptions import (
     BriefcaseCommandError,
@@ -50,12 +51,12 @@ def add_options(self, parser):
             help="The Briefcase-managed tool to upgrade. If no tool is named, all tools will be upgraded.",
         )
 
-    def get_tools_to_upgrade(self, tool_list: Set[str]) -> List[ManagedTool]:
+    def get_tools_to_upgrade(self, tool_list: set[str]) -> list[ManagedTool]:
         """Returns set of managed Tools that can be upgraded.
 
         Raises ``BriefcaseCommandError`` if user list contains any invalid tool names.
         """
-        upgrade_list: set[Type[Tool]]
+        upgrade_list: set[type[Tool]]
         tools_to_upgrade: set[ManagedTool] = set()
 
         # Validate user tool list against tool registry
@@ -94,7 +95,7 @@ def get_tools_to_upgrade(self, tool_list: Set[str]) -> List[ManagedTool]:
 
         return sorted(list(tools_to_upgrade), key=attrgetter("name"))
 
-    def __call__(self, tool_list: List[str], list_tools: bool = False, **options):
+    def __call__(self, tool_list: list[str], list_tools: bool = False, **options):
         """Perform tool upgrades or list tools qualifying for upgrade.
 
         :param tool_list: List of tool names from user to upgrade.