diff --git a/electron/main/index.ts b/electron/main/index.ts
index 3cf4facb2..ff299100d 100644
--- a/electron/main/index.ts
+++ b/electron/main/index.ts
@@ -25,6 +25,17 @@ import {
   shell,
 } from 'electron';
 import log from 'electron-log';
+
+// ==================== EPIPE error prevention ====================
+// During app shutdown, the stdout/stderr pipes may close before all log
+// writes complete. This causes uncaught EPIPE errors that crash the app.
+// Handle them gracefully by ignoring broken pipe writes.
+for (const stream of [process.stdout, process.stderr]) {
+  stream?.on?.('error', (err: NodeJS.ErrnoException) => {
+    if (err.code === 'EPIPE') return; // Silently ignore broken pipe
+  });
+}
+
 import FormData from 'form-data';
 import fsp from 'fs/promises';
 import mime from 'mime';
@@ -199,6 +210,25 @@ log.transports.file.level = 'info';
 log.transports.console.format = '[{level}]{text}';
 log.transports.file.format = '[{level}]{text}';
 
+// Catch any uncaught exceptions from broken pipes during shutdown
+// to prevent the app from crashing with EPIPE errors
+process.on('uncaughtException', (error: NodeJS.ErrnoException) => {
+  if (error.code === 'EPIPE') {
+    // Broken pipe during shutdown - safe to ignore.
+    // This happens when electron-log's console transport tries to write
+    // after the renderer process or stdout pipe has been closed.
+    return;
+  }
+  // For non-EPIPE errors, log to file (not console to avoid recursion) and re-throw
+  log.transports.file?.({
+    data: [`[UNCAUGHT] ${error.stack || error.message}`],
+    level: 'error',
+    date: new Date(),
+    variables: {},
+  } as any);
+  throw error;
+});
+
 // Disable GPU Acceleration for Windows 7
 if (os.release().startsWith('6.1')) app.disableHardwareAcceleration();
 
@@ -2234,6 +2264,9 @@ app.whenReady().then(async () => {
 app.on('window-all-closed', () => {
   log.info('window-all-closed');
 
+  // Disable console transport - all windows are closed so stdout pipe may break
+  log.transports.console.level = false;
+
   // Clean up WebView manager
   if (webViewManager) {
     webViewManager.destroy();
@@ -2271,6 +2304,12 @@ app.on('before-quit', async (event) => {
   // Prevent default quit to ensure cleanup completes
   event.preventDefault();
 
+  // Disable console transport BEFORE destroying the window.
+  // Once the window/renderer is destroyed, stdout pipe may close,
+  // causing EPIPE errors on any subsequent console.info/log writes.
+  // File transport remains active for debugging shutdown issues.
+  log.transports.console.level = false;
+
   try {
     // NOTE: Profile sync removed - we now use app userData directly for all partitions
     // No need to sync between different profile directories
diff --git a/electron/main/install-deps.ts b/electron/main/install-deps.ts
index 62ad6a4e5..201c20679 100644
--- a/electron/main/install-deps.ts
+++ b/electron/main/install-deps.ts
@@ -406,6 +406,8 @@ class InstallLogs {
         '--no-dev',
         '--cache-dir',
         getCachePath('uv_cache'),
+        '--no-build-isolation-package',
+        'llvmlite',
         ...extraArgs,
       ],
       {
diff --git a/electron/main/utils/process.ts b/electron/main/utils/process.ts
index 65bf24d51..028e4f1a7 100644
--- a/electron/main/utils/process.ts
+++ b/electron/main/utils/process.ts
@@ -631,12 +631,68 @@ export function getUvEnv(version: string): Record<string, string> {
   const prebuiltPython = getPrebuiltPythonDir();
   const pythonInstallDir = prebuiltPython || getCachePath('uv_python');
 
-  return {
+  // Ensure PATH includes common tool directories (cmake, brew, etc.)
+  // Electron GUI apps on macOS don't inherit the full shell PATH
+  const currentPath = process.env.PATH || '';
+  const extraPaths = [
+    '/usr/local/bin',
+    '/opt/homebrew/bin',
+    '/usr/bin',
+    '/bin',
+    '/usr/sbin',
+    '/sbin',
+  ];
+
+  // Add LLVM directories so llvmlite can find the correct version during builds.
+  // Prefer LLVM 20 (required by llvmlite >=0.46) over older versions.
+  const llvmPaths = [
+    '/usr/local/opt/llvm@20/bin',
+    '/opt/homebrew/opt/llvm@20/bin',
+  ];
+
+  const pathParts = currentPath.split(':');
+  // Prepend LLVM paths so they take priority over older LLVM versions
+  const allExtraPaths = [...llvmPaths, ...extraPaths];
+  const missingPaths = allExtraPaths.filter(
+    (p) => !pathParts.includes(p) && fs.existsSync(p)
+  );
+  const enhancedPath =
+    missingPaths.length > 0
+      ? [...missingPaths, ...pathParts].join(':')
+      : currentPath;
+
+  // Set LLVM_CONFIG explicitly for llvmlite builds
+  const env: Record<string, string> = {
     UV_PYTHON_INSTALL_DIR: pythonInstallDir,
     UV_TOOL_DIR: getCachePath('uv_tool'),
     UV_PROJECT_ENVIRONMENT: getVenvPath(version),
     UV_HTTP_TIMEOUT: '300',
+    PATH: enhancedPath,
   };
+
+  // Point llvmlite/cmake to the correct LLVM 20 installation.
+  // llvmlite >=0.46 requires LLVM 20. Without explicit LLVM_DIR, cmake may
+  // find an older LLVM version (e.g. 14) via system paths and fail the build.
+  // CMAKE_ARGS with -DLLVM_DIR forces cmake's find_package(LLVM) to use LLVM 20.
+  // LLVM_CONFIG provides the direct path for llvmlite's build.py.
+  const llvmPrefixes = [
+    '/usr/local/opt/llvm@20', // Intel Mac (Homebrew)
+    '/opt/homebrew/opt/llvm@20', // Apple Silicon (Homebrew)
+  ];
+
+  for (const llvmPrefix of llvmPrefixes) {
+    const llvmCmakeDir = path.join(llvmPrefix, 'lib', 'cmake', 'llvm');
+    if (fs.existsSync(llvmCmakeDir)) {
+      env.CMAKE_ARGS = `-DLLVM_DIR=${llvmCmakeDir}`;
+      const llvmConfigPath = path.join(llvmPrefix, 'bin', 'llvm-config');
+      if (fs.existsSync(llvmConfigPath)) {
+        env.LLVM_CONFIG = llvmConfigPath;
+      }
+      break;
+    }
+  }
+
+  return env;
 }
 
 export async function killProcessByName(name: string): Promise<void> {