fix: system python used instead of venv python, breaking whisper transcription

2 files changed, 36 insertions, 8 deletions

diff --git a/app/backends/envs.py b/app/backends/envs.py
index ff6d1bf..494c3e2 100644
--- a/app/backends/envs.py
+++ b/app/backends/envs.py
@@ -89,9 +89,16 @@ def env_exists(env_dir: Optional[Path] = None) -> bool:
 
 
 def is_managed_env() -> bool:
-    """True when the current process is already running inside the app venv."""
+    """True when the current process is already running inside the app venv.
+
+    Compares sys.prefix (the environment the current interpreter belongs to)
+    with ENV_DIR instead of the interpreter path: a venv's bin/python is
+    typically a symlink to the base interpreter, so resolving sys.executable
+    would also make the bare system python look like the managed env and
+    silently skip the bootstrap (and with it the requirements install).
+    """
     try:
-        return Path(sys.executable).resolve() == env_python().resolve()
+        return Path(sys.prefix).resolve() == ENV_DIR.resolve()
     except OSError:
         return False
 
diff --git a/app/tests/test_backends_envs.py b/app/tests/test_backends_envs.py
index 2f0f910..d3b35c1 100644
--- a/app/tests/test_backends_envs.py
+++ b/app/tests/test_backends_envs.py
@@ -1,7 +1,9 @@
 """Tests for the managed Python environment (backends/envs.py)."""
 
 import json
+import os
 import sys
+import tempfile
 import unittest
 from pathlib import Path
 from unittest.mock import patch
@@ -63,15 +65,34 @@ class EnvPathTests(unittest.TestCase):
                           return_value=Path("/no/such/path/python")):
             self.assertFalse(envs.env_exists())
 
-    def test_is_managed_env_compares_resolved_executable(self):
-        fake_env_python = Path("/tmp/opencode/managed-env/bin/python")
-        with patch.object(envs, "env_python", return_value=fake_env_python), \
-                patch.object(sys, "executable", str(fake_env_python)):
+    def test_is_managed_env_compares_prefix_to_env_dir(self):
+        # sys.prefix is the environment the current interpreter belongs to:
+        # the env dir for its python, the base install (/usr, ...) otherwise.
+        with patch.object(envs, "ENV_DIR", Path(sys.prefix)):
             self.assertTrue(envs.is_managed_env())
-        with patch.object(envs, "env_python", return_value=fake_env_python), \
-                patch.object(sys, "executable", "/usr/bin/python3"):
+        with patch.object(envs, "ENV_DIR",
+                          Path(tempfile.gettempdir()) / "managed-env"):
             self.assertFalse(envs.is_managed_env())
 
+    def test_is_managed_env_not_fooled_by_symlinked_venv_python(self):
+        # Regression: a venv's bin/python is a symlink to the base
+        # interpreter, so resolving sys.executable made the bare system
+        # python compare equal to env_python() and pass as the managed env —
+        # silently skipping the bootstrap (and the requirements install).
+        # The check must use sys.prefix, which stays the base install's.
+        if sys.platform == "win32":
+            self.skipTest("requires POSIX symlinks")
+        with tempfile.TemporaryDirectory() as tmp:
+            env_dir = Path(tmp) / "tts"
+            bin_dir = env_dir / "bin"
+            bin_dir.mkdir(parents=True)
+            os.symlink(sys.executable, bin_dir / "python")
+            with patch.object(envs, "ENV_DIR", env_dir):
+                # The bare system interpreter: sys.executable resolves to
+                # exactly what the venv python symlink points at, yet its
+                # prefix is not the env dir, so this must stay False.
+                self.assertFalse(envs.is_managed_env())
+
 
 class CreateEnvTests(unittest.TestCase):
     def test_create_env_invokes_venv_module(self):