From 47e6015ebd250a30b481d2f35c4944e60490ec2a Mon Sep 17 00:00:00 2001
From: Proggerdogger <143052591+Proggerdogger@users.noreply.github.com>
Date: Sun, 19 Jul 2026 13:07:50 +1000
Subject: [PATCH] Add Debian/Ubuntu preflight dependency check for
 build-shotcut.sh

Detect missing host build tools before a long compile and print one
sorted sudo apt install command. Disable with ACTION_PREFLIGHT=0.
---
 README.md                 |   8 ++
 scripts/build-shotcut.sh  |  17 ++++
 scripts/preflight-deps.sh | 186 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 211 insertions(+)
 create mode 100755 scripts/preflight-deps.sh

diff --git a/README.md b/README.md
index 6b878f5325..522278df40 100644
--- a/README.md
+++ b/README.md
@@ -53,6 +53,14 @@ The fastest way to build and try Shotcut development version is through [Qt Crea
 
 First, check dependencies are satisfied and various paths are correctly set to find different libraries and include files (Qt, MLT, frei0r and so forth).
 
+If you build with `scripts/build-shotcut.sh`, run the Debian/Ubuntu preflight checker to verify host build tools up front:
+
+```
+scripts/preflight-deps.sh
+```
+
+`build-shotcut.sh` runs this check by default before fetching or compiling. Disable it with `ACTION_PREFLIGHT=0` in `build-shotcut.conf`.
+
 #### Configure
 
 In a new directory in which to make the build (separate from the source):
diff --git a/scripts/build-shotcut.sh b/scripts/build-shotcut.sh
index 93c1864d1b..21af41f323 100755
--- a/scripts/build-shotcut.sh
+++ b/scripts/build-shotcut.sh
@@ -18,6 +18,7 @@ INSTALL_DIR="$HOME/shotcut"
 AUTO_APPEND_DATE=0
 SOURCE_DIR="$INSTALL_DIR/src"
 ACTION_CLEAN_SOURCE=0
+ACTION_PREFLIGHT=1
 ACTION_GET=1
 ACTION_CONFIGURE=1
 ACTION_COMPILE_INSTALL=1
@@ -2259,6 +2260,22 @@ End-of-shotcut-wrapper
 function perform_action {
   trace "Entering perform_action @ = $@"
   # Test that may fail goes here, before we do anything
+  if test 1 = "$ACTION_PREFLIGHT"; then
+    SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+    if [ -x "$SCRIPT_DIR/preflight-deps.sh" ]; then
+      set +e
+      "$SCRIPT_DIR/preflight-deps.sh"
+      PREFLIGHT_EXIT=$?
+      set -e
+      if test "$PREFLIGHT_EXIT" = "1"; then
+        die "Missing build dependencies. Install them with the sudo apt install command printed above, or set ACTION_PREFLIGHT=0 to skip."
+      elif test "$PREFLIGHT_EXIT" = "2"; then
+        warn "Preflight check not supported on this OS. Continuing without the dependency check."
+      fi
+    else
+      warn "Preflight script not found at $SCRIPT_DIR/preflight-deps.sh. Skipping dependency check."
+    fi
+  fi
   if test 1 = "$ACTION_CLEAN_SOURCE"; then
     clean_dirs
   fi
diff --git a/scripts/preflight-deps.sh b/scripts/preflight-deps.sh
new file mode 100755
index 0000000000..04c914a36b
--- /dev/null
+++ b/scripts/preflight-deps.sh
@@ -0,0 +1,186 @@
+#!/bin/bash
+# Check host build dependencies for scripts/build-shotcut.sh on Debian/Ubuntu.
+# Exit 0 = all present, 1 = missing packages, 2 = unsupported OS.
+# Never installs packages; only reports.
+
+set -uo pipefail
+
+OS_FAMILY=""
+MISSING_PACKAGES=()
+
+add_missing() {
+    local label="$1"
+    local pkg="$2"
+    echo "missing: ${label} (provided by apt package: ${pkg})"
+    MISSING_PACKAGES+=("$pkg")
+}
+
+have_cmd() {
+    command -v "$1" >/dev/null 2>&1
+}
+
+check_command() {
+    local cmd="$1"
+    local pkg="$2"
+    if ! have_cmd "$cmd"; then
+        add_missing "$cmd" "$pkg"
+        return 1
+    fi
+    return 0
+}
+
+check_perl_module() {
+    local module="$1"
+    local pkg="$2"
+    if ! have_cmd perl; then
+        # perl itself is reported by check_command; skip module probe.
+        return 1
+    fi
+    if ! perl -M"$module" -e 1 >/dev/null 2>&1; then
+        add_missing "perl module $module" "$pkg"
+        return 1
+    fi
+    return 0
+}
+
+check_pkg_config() {
+    local pc="$1"
+    local pkg="$2"
+    if ! have_cmd pkg-config && ! have_cmd pkgconf; then
+        # pkg-config itself is reported separately; skip PC checks.
+        return 1
+    fi
+    local pc_bin=pkg-config
+    have_cmd pkg-config || pc_bin=pkgconf
+    if ! "$pc_bin" --exists "$pc" >/dev/null 2>&1; then
+        add_missing "$pc" "$pkg"
+        return 1
+    fi
+    return 0
+}
+
+check_header() {
+    local header="$1"
+    local pkg="$2"
+    local path
+    for path in /usr/include /usr/local/include; do
+        if [ -f "$path/$header" ] || [ -d "$path/$header" ]; then
+            return 0
+        fi
+    done
+    add_missing "header $header" "$pkg"
+    return 1
+}
+
+detect_os() {
+    local id="" id_like=""
+    if [ -f /etc/os-release ]; then
+        # shellcheck disable=SC1091
+        . /etc/os-release
+        id="${ID:-}"
+        id_like="${ID_LIKE:-}"
+    fi
+
+    case "$id" in
+        debian|ubuntu|linuxmint|pop|raspbian|elementary|zorin|neon)
+            OS_FAMILY="debian"
+            return
+            ;;
+    esac
+
+    case " $id_like " in
+        *" debian "*|*" ubuntu "*)
+            OS_FAMILY="debian"
+            return
+            ;;
+    esac
+
+    if [ -f /etc/debian_version ]; then
+        OS_FAMILY="debian"
+        return
+    fi
+
+    OS_FAMILY="unsupported"
+}
+
+check_debian_deps() {
+    check_command git git || true
+    check_command make make || true
+    check_command cmake cmake || true
+    check_command ninja ninja-build || true
+    check_command meson meson || true
+    check_command python3 python3 || true
+    check_command perl perl || true
+    check_command autoconf autoconf || true
+    check_command automake automake || true
+    # Debian's libtool package provides libtoolize; libtool-bin adds the
+    # libtool wrapper. Either is enough for the autoconf build path.
+    if ! have_cmd libtool && ! have_cmd libtoolize; then
+        add_missing "libtool/libtoolize" libtool
+    fi
+    check_command autoreconf autoconf || true
+    check_command aclocal automake || true
+    check_command autopoint gettext || true
+    check_command gettext gettext || true
+    # Debian may provide pkg-config or pkgconf
+    if ! have_cmd pkg-config && ! have_cmd pkgconf; then
+        add_missing "pkg-config" pkg-config
+    fi
+    check_command gcc gcc || true
+    check_command g++ g++ || true
+    check_command glslc glslc || true
+
+    if ! have_cmd nasm && ! have_cmd yasm; then
+        add_missing "nasm or yasm" nasm
+    fi
+
+    if ! have_cmd curl && ! have_cmd wget; then
+        add_missing "curl or wget" curl
+    fi
+
+    check_perl_module "List::MoreUtils" liblist-moreutils-perl || true
+    check_perl_module "XML::Parser" libxml-parser-perl || true
+
+    # Eigen3: prefer pkg-config, fall back to headers.
+    if have_cmd pkg-config || have_cmd pkgconf; then
+        check_pkg_config eigen3 libeigen3-dev || true
+    else
+        check_header "eigen3/Eigen/Core" libeigen3-dev || \
+            check_header "Eigen/Core" libeigen3-dev || true
+    fi
+}
+
+print_install_hint() {
+    local sorted
+    # Use absolute paths: PATH may be empty in tests / constrained environments.
+    sorted=$(printf '%s\n' "${MISSING_PACKAGES[@]}" | /usr/bin/sort -u | /usr/bin/tr '\n' ' ')
+    sorted=${sorted%% }
+    echo ""
+    echo "Install missing dependencies with: sudo apt install -y ${sorted}"
+}
+
+main() {
+    detect_os
+
+    if [ "$OS_FAMILY" != "debian" ]; then
+        echo "Preflight dependency check is not supported on this OS."
+        echo "Only Debian/Ubuntu-family distributions are supported."
+        echo "Install the build tools required by scripts/build-shotcut.sh manually, then continue."
+        exit 2
+    fi
+
+    echo "Checking dependencies for Debian/Ubuntu..."
+    echo ""
+    check_debian_deps
+
+    if [ ${#MISSING_PACKAGES[@]} -eq 0 ]; then
+        echo ""
+        echo "All required dependencies are installed."
+        exit 0
+    fi
+
+    print_install_hint
+    exit 1
+}
+
+main "$@"