Three engines that shipped as terminal-only setups now install from Model
Catalogue → Engines with the existing sidecar installer, which is
generalised to take a per-engine venv interpreter, install target, import
probe and host gate.
Each engine gets DATA_DIR/engines/<id>/ with its own checkout and .venv;
every uv pip install passes --python for that venv, never the app's
interpreter. Switching the active engine only changes a pref, so moving
between engines and back cannot corrupt a working one, and uninstalling one
removes only its own folder. Tests pin both invariants for every spec.
MOSS-TTS-v1.5's [torch-runtime] extra pins torch==2.9.1+cu128, which exists
only on PyTorch's index, so its manual install and its bootstrap could never
resolve (#2015). core.torch_indexes defines the index once for the
installer and the bootstrap, and a test ties it to the app's own
pytorch-cuda index.
Install buttons appear only where the install can work: MOSS on CUDA hosts,
dots.tts off Windows (upstream publishes no Windows install). A direct POST
on an unsupported host gets a 409 with the reason. An engine with no
one-click install now points at its guide, not at a page with no Install
button.
Palash Debnath
faa3d39836
