Use uv for Python management in CI and build script

- CI: install uv via astral-sh/setup-uv, use uv to install Python
  and run the build script (replaces setup-python which fails on
  self-hosted macOS runners)
- build_sidecar.py: auto-detects uv and uses it for venv creation
  and package installation (much faster), falls back to standard
  venv + pip when uv is not available

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.gitea/workflows/build.yml

@@ -32,19 +32,15 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - name: Set up Python
+      - name: Install uv
-        uses: actions/setup-python@v5
+        uses: astral-sh/setup-uv@v4
-        with:
-          python-version: ${{ env.PYTHON_VERSION }}
-        env:
-          AGENT_TOOLSDIRECTORY: ${{ runner.temp }}/toolcache
 
-      - name: Install Python build tools
+      - name: Set up Python
-        run: python -m pip install --upgrade pip setuptools wheel
+        run: uv python install ${{ env.PYTHON_VERSION }}
 
       - name: Build sidecar
         working-directory: python
-        run: python build_sidecar.py --cpu-only
+        run: uv run --python ${{ env.PYTHON_VERSION }} python build_sidecar.py --cpu-only
 
       - name: Upload sidecar artifact
         uses: actions/upload-artifact@v3

python/build_sidecar.py

@@ -59,42 +59,67 @@ def get_target_triple() -> str:
         return f"{arch}-unknown-{system}"
 
 
+def _has_uv() -> bool:
+    """Check if uv is available."""
+    try:
+        subprocess.run(["uv", "--version"], capture_output=True, check=True)
+        return True
+    except (FileNotFoundError, subprocess.CalledProcessError):
+        return False
+
+
 def create_venv_and_install(cpu_only: bool) -> Path:
-    """Create a fresh venv and install dependencies."""
+    """Create a fresh venv and install dependencies.
+
+    Uses uv if available (much faster), falls back to standard venv + pip.
+    """
     venv_dir = BUILD_DIR / "sidecar-venv"
     if venv_dir.exists():
         shutil.rmtree(venv_dir)
 
-    print(f"[build] Creating venv at {venv_dir}")
+    use_uv = _has_uv()
-    subprocess.run([sys.executable, "-m", "venv", str(venv_dir)], check=True)
 
-    # Determine python path inside venv — use `python -m pip` instead of
+    if use_uv:
-    # calling pip directly to avoid permission errors on Windows
+        print(f"[build] Creating venv with uv at {venv_dir}")
+        subprocess.run(
+            ["uv", "venv", "--python", f"{sys.version_info.major}.{sys.version_info.minor}",
+             str(venv_dir)],
+            check=True,
+        )
+    else:
+        print(f"[build] Creating venv at {venv_dir}")
+        subprocess.run([sys.executable, "-m", "venv", str(venv_dir)], check=True)
+
+    # Determine python path inside venv
     if sys.platform == "win32":
         python = str(venv_dir / "Scripts" / "python")
     else:
         python = str(venv_dir / "bin" / "python")
 
-    def pip_install(*args: str) -> None:
+    def pkg_install(*args: str) -> None:
-        subprocess.run([python, "-m", "pip", *args], check=True)
+        if use_uv:
+            subprocess.run(["uv", "pip", "install", "--python", python, *args], check=True)
+        else:
+            subprocess.run([python, "-m", "pip", *args], check=True)
 
-    # Upgrade pip
+    if not use_uv:
-    pip_install("install", "--upgrade", "pip", "setuptools", "wheel")
+        # Upgrade pip (uv doesn't need this)
+        pkg_install("install", "--upgrade", "pip", "setuptools", "wheel")
 
     # Install torch (CPU-only to avoid bundling ~2GB of CUDA libs)
     if cpu_only:
         print("[build] Installing PyTorch (CPU-only)")
-        pip_install(
+        pkg_install(
             "install", "torch", "torchaudio",
             "--index-url", "https://download.pytorch.org/whl/cpu",
         )
     else:
         print("[build] Installing PyTorch (default, may include CUDA)")
-        pip_install("install", "torch", "torchaudio")
+        pkg_install("install", "torch", "torchaudio")
 
     # Install project and dev deps (includes pyinstaller)
     print("[build] Installing project dependencies")
-    pip_install("install", "-e", f"{SCRIPT_DIR}[dev]")
+    pkg_install("install", "-e", f"{SCRIPT_DIR}[dev]")
 
     return Path(python)