fix(installer): reuse existing whispercpp builds (#421)

docs/INSTALL.md

@@ -103,6 +103,8 @@ Options:
   --test           Run tests after installation
   --venv-dir=PATH  Specify custom virtual environment directory
   --skip-models    Skip downloading speech models during installation
+  --rebuild-whispercpp     Rebuild/reinstall pywhispercpp even if already installed
+  --no-rebuild-whispercpp  Reuse existing pywhispercpp when present (auto-mode default)
   --tag=TAG        Install specific release tag
   --help           Show this help message
 
@@ -360,6 +362,17 @@ vulkaninfo --summary | grep -i "deviceName"
 # [INFO] whisper.cpp using Vulkan GPU backend: AMD Radeon RX 6800
 ```
 
+### Reusing Existing whisper.cpp Builds
+
+When updating an existing install, the installer checks for a working `pywhispercpp`
+installation before rebuilding it. Interactive installs ask whether to rebuild, with
+the default set to no. Automatic installs reuse the existing build by default.
+
+```bash
+./install.sh --auto                         # Reuse pywhispercpp if already installed
+./install.sh --auto --rebuild-whispercpp    # Force a rebuild/reinstall
+```
+
 ### Switching Engines
 
 If you want to try a different engine after installation:

install.sh

@@ -106,6 +106,7 @@ NO_WHISPER_EXPLICIT="no"
 NON_INTERACTIVE="no"
 INTERACTIVE_MODE="yes"  # Default to interactive mode
 AUTO_MODE="no"
+REBUILD_WHISPERCPP="ask"
 HAS_NVIDIA_GPU="unknown"
 GPU_NAME=""
 GPU_MEMORY=""
@@ -117,8 +118,14 @@ VULKAN_DEVICE=""
 # If no terminal is available at all (headless/CI), fall back to automatic mode.
 if [ ! -t 0 ]; then
     if [ -e /dev/tty ] && [ -r /dev/tty ]; then
-        exec < /dev/tty
-        INTERACTIVE_MODE="ask"
+        if { true < /dev/tty; } 2>/dev/null; then
+            exec < /dev/tty
+            INTERACTIVE_MODE="ask"
+        else
+            AUTO_MODE="yes"
+            INTERACTIVE_MODE="no"
+            NON_INTERACTIVE="yes"
+        fi
     else
         AUTO_MODE="yes"
         INTERACTIVE_MODE="no"
@@ -144,6 +151,14 @@ while [[ $# -gt 0 ]]; do
             SKIP_MODELS="yes"
             shift
             ;;
+        --rebuild-whispercpp)
+            REBUILD_WHISPERCPP="yes"
+            shift
+            ;;
+        --no-rebuild-whispercpp)
+            REBUILD_WHISPERCPP="no"
+            shift
+            ;;
         --engine=*)
             SELECTED_ENGINE="${1#*=}"
             shift
@@ -180,6 +195,8 @@ while [[ $# -gt 0 ]]; do
             echo "  --test           Run tests after installation"
             echo "  --venv-dir=PATH  Specify custom virtual environment directory"
             echo "  --skip-models    Skip downloading speech models during installation"
+            echo "  --rebuild-whispercpp     Rebuild/reinstall pywhispercpp even if already installed"
+            echo "  --no-rebuild-whispercpp  Reuse existing pywhispercpp when present (auto-mode default)"
             echo "  --tag=TAG        Install specific release tag (default: latest release)"
             echo "  --help           Show this help message"
             echo ""
@@ -1881,6 +1898,56 @@ EOF
 chmod +x "$ACTIVATION_SCRIPT"
 print_info "Created activation script: $ACTIVATION_SCRIPT"
 
+is_pywhispercpp_installed() {
+    [ -x "$VENV_DIR/bin/python" ] || return 1
+    "$VENV_DIR/bin/python" -c "from pywhispercpp.model import Model" >/dev/null 2>&1
+}
+
+get_pywhispercpp_version() {
+    [ -x "$VENV_DIR/bin/python" ] || return 1
+    "$VENV_DIR/bin/python" - <<'PY' 2>/dev/null
+from importlib import metadata
+
+try:
+    print(metadata.version("pywhispercpp"))
+except metadata.PackageNotFoundError:
+    raise SystemExit(1)
+PY
+}
+
+should_rebuild_whispercpp() {
+    local INSTALLED_VERSION
+    INSTALLED_VERSION=$(get_pywhispercpp_version || true)
+
+    print_success "Found existing pywhispercpp installation${INSTALLED_VERSION:+ (version $INSTALLED_VERSION)}"
+
+    case "$REBUILD_WHISPERCPP" in
+        yes)
+            print_info "Rebuilding pywhispercpp because --rebuild-whispercpp was specified."
+            return 0
+            ;;
+        no)
+            print_info "Reusing existing pywhispercpp installation."
+            return 1
+            ;;
+    esac
+
+    if [[ "$NON_INTERACTIVE" == "yes" ]]; then
+        print_info "Non-interactive mode: reusing existing pywhispercpp installation."
+        print_info "Use --rebuild-whispercpp to force a rebuild."
+        return 1
+    fi
+
+    read -p "Rebuild/reinstall pywhispercpp? This can take several minutes. (y/N) " -n 1 -r
+    echo
+    if [[ $REPLY =~ ^[Yy]$ ]]; then
+        return 0
+    fi
+
+    print_info "Reusing existing pywhispercpp installation."
+    return 1
+}
+
 # Function to install Python package with error handling and verification
 install_python_package() {
     # Create a temporary directory for pip logs
@@ -1893,6 +1960,11 @@ install_python_package() {
     GI_TYPELIB_DETECTED=$(detect_typelib_path)
     print_info "Detected GI_TYPELIB_PATH: $GI_TYPELIB_DETECTED"
 
+    local WHISPERCPP_ALREADY_INSTALLED=false
+    if is_pywhispercpp_installed; then
+        WHISPERCPP_ALREADY_INSTALLED=true
+    fi
+
     # Function to verify package installation
     verify_package_installed() {
         local PKG_NAME="vocalinux"
@@ -1957,9 +2029,21 @@ install_python_package() {
 
                 local GPU_BACKEND="CPU"
                 local GPU_INSTALL_SUCCESS=false
+                local SKIP_WHISPERCPP_INSTALL=false
+
+                if [[ "$WHISPERCPP_ALREADY_INSTALLED" == "true" ]]; then
+                    GPU_BACKEND="existing"
+                    if should_rebuild_whispercpp; then
+                        print_info "Existing pywhispercpp will be replaced."
+                    else
+                        SKIP_WHISPERCPP_INSTALL=true
+                    fi
+                fi
 
                 # Check if user explicitly chose CPU backend in interactive mode
-                if [[ "${WHISPERCPP_BACKEND}" == "cpu" ]]; then
+                if [[ "$SKIP_WHISPERCPP_INSTALL" == "true" ]]; then
+                    print_info "Skipping pywhispercpp reinstall; existing compiled bindings remain in place."
+                elif [[ "${WHISPERCPP_BACKEND}" == "cpu" ]]; then
                     print_info "ℹ Installing CPU-only version (as requested)..."
                     GPU_BACKEND="CPU"
                 else
@@ -1989,7 +2073,7 @@ install_python_package() {
                 fi
 
                 # Fall back to CPU version if GPU install failed or no GPU detected
-                if [[ "$GPU_INSTALL_SUCCESS" != "true" ]]; then
+                if [[ "$SKIP_WHISPERCPP_INSTALL" != "true" && "$GPU_INSTALL_SUCCESS" != "true" ]]; then
                     if [[ "$GPU_BACKEND" != "CPU" ]]; then
                         print_warning "Failed to install pywhispercpp with $GPU_BACKEND support, falling back to CPU version..."
 
@@ -2015,7 +2099,11 @@ install_python_package() {
                     }
                 fi
 
-                print_success "pywhispercpp installed with $GPU_BACKEND backend"
+                if [[ "$SKIP_WHISPERCPP_INSTALL" == "true" ]]; then
+                    print_success "pywhispercpp reused from existing installation"
+                else
+                    print_success "pywhispercpp installed with $GPU_BACKEND backend"
+                fi
                 echo ""
                 ;;