feat: separate venvs for qwen-tts and faster, manage (un)installs

1 files changed, 25 insertions, 18 deletions

diff --git a/app/backends/qwen.py b/app/backends/qwen.py
index 3309c69..b2a1df4 100644
--- a/app/backends/qwen.py
+++ b/app/backends/qwen.py
@@ -4,8 +4,9 @@
 qwen-tts is a pip package providing the ``qwen-tts-demo`` server, which hosts
 ONE Qwen3-TTS model per process — CustomVoice (built-in speakers), Base
 (voice cloning) or VoiceDesign (described voice). This module sets it up
-end-to-end: pip-install the package into the managed venv. There are no
-questions to ask — the port and which model to run live in
+end-to-end: pip-install the package into its own managed venv
+(``app/envs/qwen`` — the app venv and the faster backend's never receive
+it). There are no questions to ask — the port and which model to run live in
 ``app/converter/config.py`` (the model is chosen per run on the hub's
 Generate-audiobooks screen), and only one server runs at a time.
 
@@ -46,6 +47,9 @@ from converter.clients import QWEN3_TTS_SPEAKERS
 from ui import taskview, tui
 
 QWEN_PIP_PKG = "qwen-tts"
+# The dedicated venv qwen-tts is installed into (never the app env or the
+# faster backend's).
+QWEN_ENV = envs.QWEN_ENV_DIR
 DEFAULT_PORT = 7860
 
 # The models a single demo server can host, by config.QWEN_MODEL name.
@@ -161,9 +165,9 @@ def delete_model_weights(models: Optional[List[str]] = None) -> int:
 
 
 def _is_installed() -> bool:
-    if envs.env_script("qwen-tts-demo").is_file():
+    if envs.env_script("qwen-tts-demo", QWEN_ENV).is_file():
         return True
-    return envs.module_available("qwen_tts")
+    return envs.module_available("qwen_tts", QWEN_ENV)
 
 
 def _config_port(url: str, fallback: int) -> int:
@@ -218,7 +222,8 @@ def _execute_steps(settings: dict) -> List[taskview.TaskStep]:
         return steps
 
     def install(emit, cancel):
-        rc = common.pip_install([QWEN_PIP_PKG], emit=emit, cancel=cancel)
+        rc = common.pip_install([QWEN_PIP_PKG], emit=emit, cancel=cancel,
+                                env_dir=QWEN_ENV)
         if rc != 0:
             print(f"[WARNING] pip install failed (exit {rc}); install "
                   f"{QWEN_PIP_PKG} manually")
@@ -268,7 +273,7 @@ def _collect_from_flags(args: argparse.Namespace,
 def build_parser() -> argparse.ArgumentParser:
     parser = argparse.ArgumentParser(
         description="Set up the Qwen3-TTS demo backend: pip install "
-                    "qwen-tts into the managed venv.")
+                    "qwen-tts into its managed venv (app/envs/qwen).")
     parser.add_argument("--skip-install", action="store_true",
                         help="Do not pip install qwen-tts")
     return parser
@@ -279,7 +284,7 @@ def _build_spec(model: str) -> ServerSpec:
     url = config.QWEN_API_URL
     return ServerSpec(
         "qwen", url,
-        [str(envs.env_script("qwen-tts-demo")), MODEL_REPOS[model],
+        [str(envs.env_script("qwen-tts-demo", QWEN_ENV)), MODEL_REPOS[model],
          "--ip", "127.0.0.1",
          "--port", str(_config_port(url, DEFAULT_PORT))],
         identity=desired_identity(model))
@@ -363,9 +368,9 @@ def _detect_remote(managed: bool = False):
 
 
 def _hf_download_prefix() -> Optional[List[str]]:
-    """The venv's hf CLI argv prefix (None when neither script is present)."""
+    """The qwen env's hf CLI argv prefix (None when neither script is present)."""
     for name in ("hf", "huggingface-cli"):
-        candidate = envs.env_script(name)
+        candidate = envs.env_script(name, QWEN_ENV)
         if candidate.is_file():
             return [str(candidate)]
     return None
@@ -381,7 +386,7 @@ def install_model(model: str, *, emit=None, cancel=None) -> int:
     """
     prefix = _hf_download_prefix()
     if prefix is None:
-        print("[ERROR] No hf CLI found in the managed venv; pip install "
+        print("[ERROR] No hf CLI found in the qwen venv; pip install "
               f"{QWEN_PIP_PKG} first")
         return 1
     repo = MODEL_REPOS[model]
@@ -415,12 +420,14 @@ def uninstall(*, emit=None, cancel=None) -> int:
     then delete every downloaded model.
 
     qwen-tts is a pip package (``qwen_tts`` + the ``qwen-tts-demo`` script)
-    installed into the managed venv, so uninstalling it removes the backend.
-    Any server this tool started is stopped first (best-effort). The three
-    models' weight snapshots — multi-GB directories lazily fetched into the
-    HuggingFace cache (~/.cache/huggingface/hub) — are deleted too, matching
-    the hub's confirmation dialog; only those three directories are removed,
-    never the shared cache itself.
+    installed into its own managed venv (``app/envs/qwen``, QWEN_ENV), so
+    uninstalling it removes the backend — the app venv and the faster
+    backend's env are never touched. Any server this tool started is stopped
+    first (best-effort). The three models' weight snapshots — multi-GB
+    directories lazily fetched into the HuggingFace cache
+    (~/.cache/huggingface/hub) — are deleted too, matching the hub's
+    confirmation dialog; only those three directories are removed, never the
+    shared cache itself.
 
     With EMIT given (the in-TUI task view) pip runs piped, streaming into
     EMIT, so its output never touches the terminal behind curses. CANCEL is
@@ -436,10 +443,10 @@ def uninstall(*, emit=None, cancel=None) -> int:
         servers.stop("qwen")
     if common.cancel_requested(cancel):
         return 130
-    rc = common.pip_uninstall([QWEN_PIP_PKG], emit=emit)
+    rc = common.pip_uninstall([QWEN_PIP_PKG], emit=emit, env_dir=QWEN_ENV)
     if rc != 0:
         print(f"[WARNING] pip uninstall failed (exit {rc}); remove "
-              f"{QWEN_PIP_PKG} from the managed venv manually")
+              f"{QWEN_PIP_PKG} from {QWEN_ENV} manually")
     else:
         print(f"[OK] {QWEN_PIP_PKG} removed.")
     # Weights go even when the pip step failed: the package can be