fix(python): resolve the bundle from executable_path, not the managed install

get_env_vars() and _generate_fontconfig() read the bundled fontconfig and fonts
through get_path(), i.e. the managed install, even when the caller supplied
their own binary. _load_properties() already honours executable_path for
properties.json; these two did not.

Before the floor could reject anything this silently mixed one build's fonts
into another build's launch. Once the floor is live it becomes fatal: every
launch raises UnsupportedVersion while the caller is holding a perfectly good
binary, because resolving the bundle drags in the managed install and that is
what gets version-checked.

Thread executable_path through both, matching _load_properties.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

pythonlib/tests/test_executable_path_bundle.py

@@ -0,0 +1,56 @@
+"""A caller's own binary must be resolved against itself, not the managed install.
+
+`executable_path` was honoured for launching and for properties.json, but the
+bundled fontconfig and fonts were still read from the managed install via
+get_path(). That silently mixed one build's fonts into another's launch, and
+once the version floor could actually reject something it became fatal: every
+launch raised UnsupportedVersion even though the caller had supplied a perfectly
+good binary.
+"""
+
+from pathlib import Path
+
+import pytest
+
+from camoufox import pkgman, utils
+
+
+@pytest.fixture
+def bundle(tmp_path, monkeypatch):
+    """A self-contained browser bundle, plus a managed install that must not be touched."""
+    bin_dir = tmp_path / "dist" / "bin"
+    (bin_dir / "fontconfig" / "linux").mkdir(parents=True)
+    (bin_dir / "fontconfig" / "linux" / "fonts.conf").write_text(
+        '<?xml version="1.0"?><fontconfig><dir prefix="cwd">fonts</dir></fontconfig>'
+    )
+    (bin_dir / "fonts").mkdir()
+
+    def explode(*_args, **_kwargs):
+        raise AssertionError("resolved against the managed install despite executable_path")
+
+    monkeypatch.setattr(pkgman, "get_path", explode)
+    monkeypatch.setattr(utils, "get_path", explode)
+    monkeypatch.setattr(utils, "INSTALL_DIR", tmp_path / "cache")
+    monkeypatch.setattr(utils, "OS_NAME", "lin")
+    return bin_dir
+
+
+def test_fontconfig_comes_from_the_supplied_bundle(bundle, monkeypatch):
+    env = utils.get_env_vars({}, "lin", path=bundle / "camoufox-bin")
+
+    generated = Path(env["FONTCONFIG_FILE"])
+    assert generated.is_file()
+    # The bundled conf's cwd-relative <dir> is rewritten to this bundle's fonts.
+    assert str(bundle / "fonts") in generated.read_text()
+
+
+def test_managed_install_is_used_when_no_path_is_given(tmp_path, monkeypatch):
+    """Without executable_path the managed install is still the source."""
+    calls = []
+    monkeypatch.setattr(utils, "OS_NAME", "lin")
+    monkeypatch.setattr(utils, "get_path", lambda *a: calls.append(a) or "/nonexistent")
+
+    with pytest.raises(Exception):
+        utils.get_env_vars({}, "lin")
+
+    assert calls, "should have consulted the managed install"

pythonlib/tests/test_humanize.py

@@ -31,7 +31,7 @@ def captured_launch_config(monkeypatch):
     monkeypatch.setattr(utils, "launch_path", lambda *_args, **_kwargs: "/camoufox")
     monkeypatch.setattr(utils.LeakWarning, "warn", lambda *_args, **_kwargs: None)
 
-    def capture_env(config, _target_os):
+    def capture_env(config, _target_os, **_kwargs):
         captured.clear()
         captured.update(config)
         return {}