Merge origin/master into feat/darwin-trl

Resolve includeDarwin conflict in backend-matrix.yml: keep both the trl and
the merged liquid-audio darwin entries (additive).

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
Assisted-by: Claude:opus-4.8 [Claude Code]

.github/backend-matrix.yml

@@ -4974,6 +4974,9 @@ includeDarwin:
   - backend: "kitten-tts"
     tag-suffix: "-metal-darwin-arm64-kitten-tts"
     build-type: "mps"
+  - backend: "trl"
+    tag-suffix: "-metal-darwin-arm64-trl"
+    build-type: "mps"
   - backend: "liquid-audio"
     tag-suffix: "-metal-darwin-arm64-liquid-audio"
     build-type: "mps"

backend/index.yaml

@@ -5295,6 +5295,7 @@
     nvidia: "cuda12-trl"
     nvidia-cuda-12: "cuda12-trl"
     nvidia-cuda-13: "cuda13-trl"
+    metal: "metal-trl"
 ## TRL backend images
 - !!merge <<: *trl
   name: "cpu-trl"
@@ -5326,6 +5327,16 @@
   uri: "quay.io/go-skynet/local-ai-backends:master-gpu-nvidia-cuda-13-trl"
   mirrors:
     - localai/localai-backends:master-gpu-nvidia-cuda-13-trl
+- !!merge <<: *trl
+  name: "metal-trl"
+  uri: "quay.io/go-skynet/local-ai-backends:latest-metal-darwin-arm64-trl"
+  mirrors:
+    - localai/localai-backends:latest-metal-darwin-arm64-trl
+- !!merge <<: *trl
+  name: "metal-trl-development"
+  uri: "quay.io/go-skynet/local-ai-backends:master-metal-darwin-arm64-trl"
+  mirrors:
+    - localai/localai-backends:master-metal-darwin-arm64-trl
 ## llama.cpp quantization backend
 - &llama-cpp-quantization
   name: "llama-cpp-quantization"

backend/python/trl/install.sh

@@ -8,7 +8,13 @@ else
     source $backend_dir/../common/libbackend.sh
 fi
 
-EXTRA_PIP_INSTALL_FLAGS+=" --upgrade --index-strategy=unsafe-first-match"
+EXTRA_PIP_INSTALL_FLAGS+=" --upgrade"
+# --index-strategy is a uv-only flag. The darwin/MPS build installs with pip
+# (USE_PIP=true in scripts/build/python-darwin.sh), which rejects it. Only add
+# it when uv is the installer, keeping the Linux/CUDA resolution unchanged.
+if [ "x${USE_PIP:-}" != "xtrue" ]; then
+    EXTRA_PIP_INSTALL_FLAGS+=" --index-strategy=unsafe-first-match"
+fi
 installRequirements
 
 # Fetch convert_hf_to_gguf.py and gguf package from the same llama.cpp version

backend/python/trl/requirements-mps.txt

@@ -0,0 +1,12 @@
+torch==2.10.0
+trl
+peft
+datasets>=3.0.0
+transformers>=4.56.2
+accelerate>=1.4.0
+huggingface-hub>=1.3.0
+sentencepiece
+# Note: bitsandbytes is intentionally omitted on MPS. It is only used by the
+# CUDA (cublas) variants for 8-bit/4-bit quantization and has poor support on
+# Apple Silicon. torch here uses the plain PyPI wheels, which ship MPS support
+# on macOS arm64.