Use isolated virtual environments for app builds.

.github/workflows/check-pr-template.yml

@@ -10,4 +10,4 @@ permissions:
 jobs:
   check-pr-template:
     name: Check PR template
-    uses: beeware/.github/.github/workflows/pr-checklist.yml@741cc5a311012ee0ee195938889a337449d01eeb  # main
+    uses: beeware/.github/.github/workflows/pr-checklist.yml@04ef7a6aca716616670c1ce5232d4aa3061f5c5e  # main

.github/workflows/ci.yml

@@ -33,7 +33,7 @@ permissions:
 jobs:
   pre-commit:
     name: Pre-commit checks
-    uses: beeware/.github/.github/workflows/pre-commit-run.yml@741cc5a311012ee0ee195938889a337449d01eeb  # main
+    uses: beeware/.github/.github/workflows/pre-commit-run.yml@04ef7a6aca716616670c1ce5232d4aa3061f5c5e  # main
     with:
       pre-commit-source: "--group pre-commit"
 
@@ -60,7 +60,7 @@ jobs:
 
   towncrier:
     name: Check towncrier
-    uses: beeware/.github/.github/workflows/towncrier-run.yml@741cc5a311012ee0ee195938889a337449d01eeb  # main
+    uses: beeware/.github/.github/workflows/towncrier-run.yml@04ef7a6aca716616670c1ce5232d4aa3061f5c5e  # main
     permissions:
       contents: read
       pull-requests: write
@@ -79,7 +79,7 @@ jobs:
         - ""  # root briefcase package
         - "debugger"
         - "automation"
-    uses: beeware/.github/.github/workflows/python-package-create.yml@741cc5a311012ee0ee195938889a337449d01eeb  # main
+    uses: beeware/.github/.github/workflows/python-package-create.yml@04ef7a6aca716616670c1ce5232d4aa3061f5c5e  # main
     with:
       build-subdirectory: ${{ matrix.subdir }}
       attest: ${{ inputs.attest-package }}
@@ -238,7 +238,7 @@ jobs:
   verify-projects:
     name: Verify project
     needs: [ package, unit-tests ]
-    uses: beeware/.github/.github/workflows/app-create-verify.yml@741cc5a311012ee0ee195938889a337449d01eeb  # main
+    uses: beeware/.github/.github/workflows/app-create-verify.yml@04ef7a6aca716616670c1ce5232d4aa3061f5c5e  # main
     with:
       runner-os: ${{ matrix.runner-os }}
       framework: ${{ matrix.framework }}
@@ -251,7 +251,7 @@ jobs:
   verify-apps:
     name: Build app
     needs: [ package, unit-tests ]
-    uses: beeware/.github/.github/workflows/app-build-verify.yml@741cc5a311012ee0ee195938889a337449d01eeb  # main
+    uses: beeware/.github/.github/workflows/app-build-verify.yml@04ef7a6aca716616670c1ce5232d4aa3061f5c5e  # main
     with:
       # Builds on Linux must use System Python; otherwise, fall back to version all GUI toolkits support
       python-version: ${{ startsWith(matrix.runner-os, 'ubuntu') && 'system' || '3.12' }}

.github/workflows/dependabot-changenote.yml

@@ -11,7 +11,7 @@ permissions:
 jobs:
   changenote:
     name: Dependabot Change Note
-    uses: beeware/.github/.github/workflows/dependabot-changenote.yml@741cc5a311012ee0ee195938889a337449d01eeb  # main
+    uses: beeware/.github/.github/workflows/dependabot-changenote.yml@04ef7a6aca716616670c1ce5232d4aa3061f5c5e  # main
     secrets:
       BRUTUS_PAT_TOKEN: ${{ secrets.BRUTUS_PAT_TOKEN }}
     with:

.github/workflows/release.yml

@@ -22,7 +22,7 @@ jobs:
     permissions:
       contents: read
     name: Verify Docs Build
-    uses: beeware/.github/.github/workflows/docs-build-verify.yml@741cc5a311012ee0ee195938889a337449d01eeb  # main
+    uses: beeware/.github/.github/workflows/docs-build-verify.yml@04ef7a6aca716616670c1ce5232d4aa3061f5c5e  # main
     secrets:
       RTD_API_TOKEN: ${{ secrets.RTD_API_TOKEN }}
     with:

changes/2967.feature.md

@@ -0,0 +1 @@
+Apps now use an isolated environment when installing requirements. This removes a source of error where the environment running Briefcase could have an impact the packages installed into a standalone app.

changes/2967.removal.md

@@ -0,0 +1 @@
+Windows apps now enforce the use of binary artefacts when installing Python dependencies. If you have a dependency that is only available as a source tarball, ask the upstream maintainer to publish a wheel on PyPI; alternatively, you can build a wheel locally (using `pip wheel`), and then add the directory that contains the wheel to your requirements using `requirement_installer_args`.

docs/en/reference/configuration.md

@@ -107,7 +107,7 @@ The contact email address for the person or organization responsible for the pro
 
 #### `env_manager`
 
-**EXPERIMENTAL** This is an experimental feature. It is currently only used by developer mode.
+**EXPERIMENTAL** This is an experimental feature.
 
 The environment manager to use when creating isolated Python environments and installing requirements. Must be one of:
 
@@ -179,7 +179,7 @@ cleanup_paths = [
     "path/to/unneeded_file.txt",
     "path/to/unneeded_directory",
     "path/**/*.exe",
-    "{app.formal_name}/content/extra.doc"
+    "{app.formal_name}/content/extra.doc",
 ]
 ```
 
@@ -330,23 +330,24 @@ Any PEP 508 version specifier is legal. For example:
   ```python
   requires = [
       "pillow==9.1.0",
-      "--no-binary", "pillow",
+      "--no-binary",
+      "pillow",
   ]
   ```
 
 - Git repository:
   ```python
-  requires=["git+https://github.com/beeware/briefcase.git"]
+  requires = ["git+https://github.com/beeware/briefcase.git"]
   ```
 
 - Local directory:
   ```python
-  requires=["mysrc/myapp"]
+  requires = ["mysrc/myapp"]
   ```
 
 - Local wheel file:
   ```python
-  requires=["fullpath/wheelfile.whl"]
+  requires = ["fullpath/wheelfile.whl"]
   ```
 
 #### `revision`