diff --git a/.fmf/version b/.fmf/version
new file mode 100644
index 0000000..d00491f
--- /dev/null
+++ b/.fmf/version
@@ -0,0 +1 @@
+1
diff --git a/gating.yaml b/gating.yaml
index d353613..f707dc8 100644
--- a/gating.yaml
+++ b/gating.yaml
@@ -4,3 +4,4 @@ product_versions:
 decision_context: osci_compose_gate
 rules:
   - !PassingTestCaseRule {test_case_name: desktop-qe.desktop-ci.tier1-gating.functional}
+  - !PassingTestCaseRule {test_case_name: osci.brew-build.tier0.functional}
diff --git a/plan.fmf b/plan.fmf
new file mode 100644
index 0000000..4604c6a
--- /dev/null
+++ b/plan.fmf
@@ -0,0 +1,108 @@
+/plan-graphics-sanity-test:
+  summary: Graphics stack smoke test plan
+  discover:
+    how: fmf
+  provision:
+    how: local
+  prepare:
+    how: shell
+    script: |
+      set -x  # Enable verbose logging
+      echo "========================================"
+      echo "Installing desktop environment and graphics dependencies"
+      echo "Architecture: $(uname -m)"
+      echo "OS: $(cat /etc/redhat-release)"
+      echo "========================================"
+
+      # Install full GNOME desktop environment (minimal)
+      echo "Step 1: Installing GNOME desktop environment..."
+      dnf groupinstall -y "Server with GUI" || \
+      dnf groupinstall -y "GNOME Desktop" || \
+      dnf install -y @gnome-desktop
+
+      # Install Wayland session specifically
+      echo "Step 2: Installing Wayland session components..."
+      dnf install -y \
+        gnome-session-wayland-session \
+        gnome-shell \
+        mutter \
+        xorg-x11-server-Xwayland
+
+      # Install graphics stack dependencies
+      echo "Step 3: Installing graphics stack dependencies..."
+      dnf install -y \
+        mesa-dri-drivers \
+        mesa-libGL \
+        mesa-libEGL \
+        mesa-libGLES \
+        mesa-vulkan-drivers \
+        gtk3 \
+        gtk4 \
+        xwayland-run \
+        mesa-demos \
+        python3-gobject \
+        glx-utils
+
+      # Install optional packages
+      echo "Step 4: Installing optional packages..."
+      dnf install -y gtk3-devel gtk4-devel xterm glxgears || true
+
+      # Verify key components
+      echo "Step 5: Verifying installation..."
+      echo "  mutter: $(which mutter || echo 'NOT FOUND')"
+      echo "  xwfb-run: $(which xwfb-run || echo 'NOT FOUND')"
+      echo "  glxinfo: $(which glxinfo || echo 'NOT FOUND')"
+      echo "  Software renderer: $(ls /usr/lib64/dri/swrast_dri.so 2>/dev/null || echo 'NOT FOUND')"
+
+      echo "========================================"
+      echo "Installation complete"
+      echo "========================================"
+  execute:
+    how: tmt
+
+/tests:
+    /infrastructure-test:
+      summary: Graphics infrastructure test (Phases 1-3)
+      description: |
+        Validates graphics stack infrastructure:
+        - Phase 1: System info and prerequisites
+        - Phase 2: Library initialization (Mesa, GTK)
+        - Phase 3: Headless compositor and GL context
+
+        This test verifies that the graphics stack is properly set up
+        before running actual rendering tests.
+      test: SKIP_INSTALL=1 ./tests/graphics-smoke-test-tmt.sh --phase=1-3
+      tty: true
+      order: 10
+      duration: 4m
+      contact:
+        - Peter Kopec <pekopec@redhat.com>
+      component:
+        - mesa
+        - gtk3
+        - mutter
+        - xwayland
+
+    /rendering-test:
+      summary: Graphics rendering verification (Phase 4)
+      description: |
+        Validates actual graphics rendering with visual verification:
+        - GTK3/GTK4 application startup
+        - GTK4 rendering test with default renderer
+        - GTK4 rendering test with NGL renderer
+        - Visual verification via PNG color analysis
+        - glxgears FPS test
+
+        Detects the s390x Mesa 25.2.7-3 black screen bug where
+        GTK4 apps show black windows with default renderer but
+        work correctly with GSK_RENDERER=ngl.
+      test: SKIP_INSTALL=1 ./tests/graphics-smoke-test-tmt.sh --phase=4
+      tty: true
+      order: 20
+      duration: 8m
+      contact:
+        - Peter Kopec <pekopec@redhat.com>
+      component:
+        - mesa
+        - gtk4
+        - mutter
diff --git a/tests/README.md b/tests/README.md
new file mode 100644
index 0000000..9e0a469
--- /dev/null
+++ b/tests/README.md
@@ -0,0 +1,321 @@
+# Universal Mesa Graphics Smoke Test
+
+Multi-architecture headless graphics stack testing for Mesa, GTK3/GTK4, and the GNOME compositor.
+
+## Overview
+
+This test suite validates the graphics stack functionality across **4 CPU architectures**:
+- **x86_64** (Intel/AMD)
+- **aarch64** (ARM 64-bit)
+- **ppc64le** (PowerPC Little-Endian)
+- **s390x** (IBM Z System)
+
+The tests run entirely **headless** (no physical display required) using `xwfb-run` (Xwayland framebuffer) for testing on bare metal, VMs, or CI infrastructure.
+
+## What It Tests
+
+### Phase 1: System Information & Prerequisites
+- Architecture and kernel information
+- CPU, memory, and hardware details
+- Required package installation verification:
+  - `mesa-dri-drivers`
+  - `gtk3`, `gtk4`
+  - `mutter` (Wayland compositor)
+  - `xwayland-run` (headless testing framework)
+  - Mesa GL/EGL/Vulkan drivers
+
+### Phase 2: Graphics Library Initialization
+- Mesa GL library loading (`libGL.so.1`)
+- GTK3/GTK4 Python bindings import test
+- Software renderer availability check (llvmpipe/swrast)
+
+### Phase 3: Headless Graphics Stack
+- Wayland compositor startup (`xwfb-run`)
+- X11/Xwayland compatibility layer
+- OpenGL context creation
+- Renderer detection (`glxinfo`)
+  - Reports vendor, renderer, and GL version
+
+### Phase 4: Application Rendering Tests
+- **GTK3 Demo**: Application startup and rendering
+  - `gtk3-demo --list` (enumerate demos)
+  - `gtk3-demo --run=textscroll --autoquit` (actual demo execution)
+
+- **GTK4 Demo**: Application startup and rendering
+  - `gtk4-demo --list` (enumerate demos)
+  - `gtk4-demo --run=textscroll --autoquit` (actual demo execution)
+
+- **GTK4 Visual Verification** (detects rendering bugs):
+  - Renders colored shapes (red, green, blue rectangles + yellow circle)
+  - Saves PNG screenshot
+  - Analyzes color diversity to detect black screen bug
+  - Tests **both** default renderer and NGL renderer
+
+- **glxgears**: OpenGL performance test
+  - Runs for 25 seconds
+  - Verifies FPS output and GL rendering
+
+## Known Issues Detected
+
+### s390x Mesa 25.2.7-3 Black Screen Bug
+**Symptom**: GTK4 applications display black windows with the default renderer.
+
+**Detection**: The visual verification test counts unique colors in the rendered PNG. A properly rendered image has 50+ unique color values; a black screen has <10.
+
+**Workaround**: Setting `GSK_RENDERER=ngl` forces the NGL (new GL) renderer and fixes the issue.
+
+This test suite automatically detects this failure and tests the NGL workaround.
+
+## Architecture
+
+```
+universal_sanity_test/
+├── main.fmf                          # TMT test definition (Testing Farm)
+├── graphics-smoke-test-rhts.sh      # Main test script with RHTS reporting
+├── gtk4_render_test.py              # GTK4 visual verification app
+└── README.md                         # This file
+```
+
+### Test Framework: TMT (Test Management Tool)
+
+The `main.fmf` file defines:
+- **Plan**: `plan-graphics-sanity-test`
+  - Provisioning: `local` (runs on current system)
+  - Preparation: Installs GNOME desktop and graphics dependencies
+  - Execution: TMT test runner
+
+- **Test 1**: `infrastructure-test` (Phases 1-3)
+  - Duration: 4 minutes
+  - Order: 10 (runs first)
+  - Tags: `CI-Tier-1`, `graphics`, `infrastructure`, `multiarch`
+
+- **Test 2**: `rendering-test` (Phase 4)
+  - Duration: 8 minutes
+  - Order: 20 (runs second)
+  - Tags: `CI-Tier-1`, `graphics`, `rendering`, `visual-verification`, `multiarch`
+
+### RHTS Reporting
+
+All test results are reported via `tmt-report-result` for integration with:
+- Testing Farm
+- RHEL Testing Infrastructure
+- CI/CD pipelines
+
+Each test reports one of:
+- **PASS**: Test succeeded
+- **FAIL**: Critical test failed
+- **WARN**: Optional test failed (doesn't affect overall result)
+- **SKIP**: Test was skipped (dependency not available)
+
+## Usage
+
+### Run All Tests (Recommended)
+```bash
+./graphics-smoke-test-rhts.sh
+```
+
+### Run Only Infrastructure Tests (Phases 1-3)
+```bash
+./graphics-smoke-test-rhts.sh --phase=1-3
+```
+
+### Run Only Rendering Tests (Phase 4)
+```bash
+./graphics-smoke-test-rhts.sh --phase=4
+```
+
+### Run with TMT (Testing Farm)
+```bash
+tmt run --all
+```
+
+### Run Specific TMT Test
+```bash
+# Infrastructure only
+tmt run test --name /tests/infrastructure-test
+
+# Rendering only
+tmt run test --name /tests/rendering-test
+```
+
+## Requirements
+
+### System Requirements
+- RHEL 9+, Fedora 35+, or CentOS Stream 9+
+- Supported architectures: x86_64, aarch64, ppc64le, s390x
+- No physical display required (fully headless)
+
+### Required Packages
+The test automatically installs these if missing:
+- `mesa-dri-drivers` - Mesa DRI drivers (required)
+- `mesa-libGL`, `mesa-libEGL`, `mesa-libGLES` - Mesa GL libraries
+- `mesa-vulkan-drivers` - Mesa Vulkan support
+- `gtk3`, `gtk4` - GTK widget toolkit
+- `xwayland-run` - Headless X server wrapper
+- `mutter` - GNOME Wayland compositor
+- `gnome-session-wayland-session` - Wayland session components
+- `mesa-demos` - GL utilities (glxinfo, glxgears)
+- `python3-gobject` - Python GTK bindings
+
+### Optional Packages
+- `gtk3-devel`, `gtk4-devel` - Development tools
+- `glx-utils` - GLX utilities
+- `xterm` - Terminal emulator
+
+## Output
+
+### Logs Directory
+All logs are saved to: `/tmp/graphics-test-logs/`
+
+Key files:
+- `00-master-test.log` - Complete test output
+- `prereq_system-check.log` - System information and prerequisites
+- `app_gtk4-render-test-default.log` - GTK4 default renderer test
+- `gtk4_render_test_default.png` - Visual verification screenshot
+- `gtk4_render_test_ngl.png` - NGL renderer screenshot
+
+### Test Results Summary
+The script outputs:
+- Individual test results (PASS/FAIL/WARN/SKIP)
+- OpenGL renderer information
+- List of generated logs and screenshots
+- Overall result: PASS or FAIL
+
+### RHTS Artifacts
+The following artifacts are submitted to Testing Farm:
+- Master log file
+- All PNG screenshots (visual evidence)
+- Failed test logs (for debugging)
+
+## Customization
+
+### Environment Variables
+```bash
+# Set custom log directory
+LOGDIR=/var/log/graphics-test ./graphics-smoke-test-rhts.sh
+
+# Disable verbose logging
+VERBOSE=0 ./graphics-smoke-test-rhts.sh
+
+# Force specific GTK renderer
+GSK_RENDERER=ngl ./graphics-smoke-test-rhts.sh --phase=4
+```
+
+### Manual GTK4 Render Test
+```bash
+# Test with default renderer
+xwfb-run -w 2 -- python3 gtk4_render_test.py output.png
+
+# Test with NGL renderer
+xwfb-run -w 2 -- python3 gtk4_render_test.py output_ngl.png --renderer=ngl
+
+# Test with other renderers
+xwfb-run -w 2 -- python3 gtk4_render_test.py output_cairo.png --renderer=cairo
+xwfb-run -w 2 -- python3 gtk4_render_test.py output_vulkan.png --renderer=vulkan
+```
+
+## Exit Codes
+
+- `0` - All critical tests passed
+- `1` - One or more critical tests failed
+
+## Integration Examples
+
+### CI/CD Pipeline (.gitlab-ci.yml)
+```yaml
+graphics-test:
+  stage: test
+  script:
+    - cd universal_sanity_test
+    - ./graphics-smoke-test-rhts.sh
+  artifacts:
+    when: always
+    paths:
+      - /tmp/graphics-test-logs/
+    expire_in: 7 days
+  tags:
+    - multiarch
+```
+
+### Testing Farm
+```yaml
+plans:
+  - name: graphics-smoke-test
+    discover:
+      how: fmf
+    execute:
+      how: tmt
+```
+
+## Troubleshooting
+
+### Tests Fail to Start
+**Problem**: Missing dependencies
+
+**Solution**: The script auto-installs packages, but you can pre-install:
+```bash
+dnf install -y mesa-dri-drivers gtk4 mutter xwayland-run
+```
+
+### Black Screen Detected (s390x)
+**Problem**: GTK4 apps show black windows
+
+**Solution**: This is a known Mesa bug on s390x. Use NGL renderer:
+```bash
+GSK_RENDERER=ngl gtk4-app
+```
+
+### glxgears Timeout
+**Problem**: `glxgears` test times out or shows no FPS
+
+**Solution**: Check renderer:
+```bash
+xwfb-run -w 2 -- glxinfo | grep -i renderer
+```
+Ensure software renderer (llvmpipe/swrast) is available.
+
+### xwfb-run Not Found
+**Problem**: `xwayland-run` package not installed
+
+**Solution**:
+```bash
+dnf install -y xwayland-run
+```
+
+## Development & Contributions
+
+### Test Structure
+Each test uses the `run_test()` wrapper:
+```bash
+run_test "test-name" \
+    "command to execute" \
+    "yes|no (critical)"
+```
+
+### Adding New Tests
+1. Add test to appropriate phase function in `graphics-smoke-test-rhts.sh`
+2. Use `run_test()` for automatic RHTS reporting
+3. Update this README with test description
+
+### Color Coding
+- Blue: Section headers
+- Green: Pass
+- Yellow: Warning (non-critical failure)
+- Red: Fail (critical failure)
+
+## License
+
+Testing infrastructure for Mesa and GNOME graphics stack.
+
+## Contact
+
+- **Maintainer**: Peter Kopec pekopec@redhat.com
+- **Components Tested**: mesa, gtk3, gtk4, mutter, xwayland
+- **Tags**: CI-Tier-1, graphics, multiarch, infrastructure, rendering
+
+## See Also
+
+- [TMT Documentation](https://tmt.readthedocs.io/)
+- [Mesa Project](https://www.mesa3d.org/)
+- [GTK Documentation](https://www.gtk.org/)
+- [GNOME Mutter](https://gitlab.gnome.org/GNOME/mutter)
diff --git a/tests/graphics-smoke-test-tmt.sh b/tests/graphics-smoke-test-tmt.sh
new file mode 100755
index 0000000..f97f392
--- /dev/null
+++ b/tests/graphics-smoke-test-tmt.sh
@@ -0,0 +1,794 @@
+#!/bin/bash
+#
+# Cross-Architecture Graphics Smoke Test with TMT Reporting
+# Works on: x86_64, aarch64, ppc64le, s390x
+# OS: RHEL 9+, Fedora 35+
+#
+# Designed for Testing Farm / TMT environment
+# Reports each test result using tmt-report-result
+#
+
+#set -e
+set -x  # Enable verbose mode - show all commands
+
+# =============================================================================
+# Configuration
+# =============================================================================
+TEST_TIMEOUT=30
+LOGDIR=${LOGDIR:-/tmp/graphics-test-logs}
+OVERALL_RESULT="PASS"
+VERBOSE=${VERBOSE:-1}  # Verbose logging enabled by default
+
+# Create log directory
+mkdir -p "$LOGDIR"
+
+# Log everything to a master log file
+exec > >(tee -a "$LOGDIR/00-master-test.log") 2>&1
+
+# Color output (disabled if not a terminal)
+if [ -t 1 ]; then
+    RED='\033[0;31m'
+    GREEN='\033[0;32m'
+    YELLOW='\033[1;33m'
+    BLUE='\033[0;34m'
+    NC='\033[0m'
+else
+    RED=''
+    GREEN=''
+    YELLOW=''
+    BLUE=''
+    NC=''
+fi
+
+# =============================================================================
+# Helper Functions
+# =============================================================================
+
+# TMT reporting helper
+tmt_report() {
+    local test_name="$1"
+    local result="$2"      # PASS/FAIL/WARN/SKIP
+    local logfile="$3"
+
+    echo -e "${BLUE}[TMT]${NC} Reporting: $test_name = $result"
+
+    if command -v tmt-report-result >/dev/null 2>&1; then
+        tmt-report-result -o "$logfile" "$test_name" "$result"
+    else
+        # Fallback when not in TMT environment
+        echo "TMT_REPORT: $test_name $result $logfile"
+    fi
+
+    # Track overall failure (SKIP doesn't affect overall result)
+    if [ "$result" == "FAIL" ]; then
+        OVERALL_RESULT="FAIL"
+    fi
+}
+
+# TMT log submission helper (for screenshots, images, etc.)
+tmt_submit() {
+    local file="$1"
+    local description="${2:-$(basename $file)}"
+
+    if [ ! -f "$file" ]; then
+        echo -e "${YELLOW}[TMT]${NC} Skip submit: $file (not found)"
+        return 1
+    fi
+
+    echo -e "${BLUE}[TMT]${NC} Submitting: $description"
+
+    if command -v tmt-file-submit >/dev/null 2>&1; then
+        tmt-file-submit -l "$file"
+    else
+        # Fallback when not in TMT environment
+        echo "TMT_SUBMIT: $file ($description)"
+    fi
+}
+
+# Test execution wrapper
+run_test() {
+    local test_name="$1"
+    local test_cmd="$2"
+    local critical="${3:-yes}"  # yes/no
+    local logfile="$LOGDIR/${test_name//\//_}"  # Replace / with _
+    logfile="${logfile//[: ]/_}.log"            # Replace : and space with _
+
+    echo "========================================"
+    echo "Running: $test_name"
+    echo "Command: $test_cmd"
+    echo "Log: $logfile"
+    echo -n "Result: "
+
+    if eval "$test_cmd" >"$logfile" 2>&1; then
+        echo -e "${GREEN}PASS${NC}"
+
+        # Show last few lines of output if verbose
+        if [ "$VERBOSE" == "1" ] && [ -s "$logfile" ]; then
+            echo "  Last output lines:"
+            tail -5 "$logfile" | sed 's/^/    /'
+        fi
+        tmt_report "$test_name" "PASS" "$logfile"
+        return 0
+    else
+        local exit_code=$?
+        echo $exit_code >> "$logfile"
+        if [ "$critical" == "yes" ]; then
+            echo -e "${RED}FAIL${NC} (exit code: $exit_code)"
+
+            # Always show failure details
+            echo "  Error details:"
+            tail -20 "$logfile" | sed 's/^/    /'
+
+            tmt_report "$test_name" "FAIL" "$logfile"
+            return 1
+        else
+            echo -e "${YELLOW}WARN${NC} (optional, exit code: $exit_code)"
+
+            # Show warning details if verbose
+            if [ "$VERBOSE" == "1" ] && [ -s "$logfile" ]; then
+                echo "  Warning details:"
+                tail -10 "$logfile" | sed 's/^/    /'
+            fi
+
+            tmt_report "$test_name" "WARN" "$logfile"
+            return 0
+        fi
+    fi
+}
+
+# =============================================================================
+# Dependency Installation
+# =============================================================================
+
+install_dependencies() {
+    local logfile="$LOGDIR/00-install-dependencies.log"
+
+    echo -e "${BLUE}========================================${NC}"
+    echo -e "${BLUE}  Installing Dependencies${NC}"
+    echo -e "${BLUE}========================================${NC}"
+
+    # Required packages
+    local required_packages=(
+        mesa-dri-drivers
+        mesa-libGL
+        mesa-libEGL
+        gtk3
+        gtk4
+        xwayland-run
+        mutter
+        mesa-demos
+        python3-gobject
+    )
+
+    # Optional packages
+    local optional_packages=(
+        gtk3-devel
+        gtk4-devel
+        gtk4-devel-tools
+        xterm
+    )
+
+    echo "Installing required packages..." | tee "$logfile"
+
+    if command -v dnf &>/dev/null; then
+        # Install required packages
+        if dnf install -y "${required_packages[@]}" >>"$logfile" 2>&1; then
+            echo -e "${GREEN}✓${NC} Required packages installed"
+            tmt_report "install-dependencies" "PASS" "$logfile"
+        else
+            echo -e "${RED}✗${NC} Failed to install required packages"
+            tmt_report "install-dependencies" "FAIL" "$logfile"
+            echo "Check log: $logfile"
+            exit 1
+        fi
+
+        # Install optional packages (non-fatal)
+        echo "Installing optional packages..." | tee -a "$logfile"
+        for pkg in "${optional_packages[@]}"; do
+            dnf install -y "$pkg" >>"$logfile" 2>&1 || echo "  Skipped: $pkg"
+        done
+         tmt_submit "$logfile" "Optional extra dependencies"
+    else
+        echo -e "${RED}✗${NC} dnf package manager not found"
+        tmt_report "install-dependencies" "FAIL" "$logfile"
+        exit 1
+    fi
+
+    echo
+}
+
+# =============================================================================
+# Phase Functions
+# =============================================================================
+
+run_phases_1_to_3() {
+    echo -e "${BLUE}========================================${NC}"
+    echo -e "${BLUE}  Phases 1-3: Infrastructure Tests${NC}"
+    echo -e "${BLUE}========================================${NC}"
+    echo "Architecture:  $(uname -m)"
+    echo "Kernel:        $(uname -r)"
+    echo "OS:            $(cat /etc/redhat-release 2>/dev/null || cat /etc/os-release | grep PRETTY_NAME | cut -d'"' -f2)"
+    echo "Log directory: $LOGDIR"
+    echo "Date:          $(date)"
+    echo -e "${BLUE}========================================${NC}"
+    echo
+
+    # Environment debugging
+    echo -e "${BLUE}Environment Check:${NC}"
+    echo "Display:       ${DISPLAY:-not set}"
+    echo "Wayland:       ${WAYLAND_DISPLAY:-not set}"
+    echo "XDG Runtime:   ${XDG_RUNTIME_DIR:-not set}"
+    echo "Session type:  ${XDG_SESSION_TYPE:-not set}"
+    echo
+
+    # Check what's already available
+    echo -e "${BLUE}Pre-flight Check:${NC}"
+    echo "  mutter:      $(which mutter 2>/dev/null || echo 'NOT FOUND')"
+    echo "  xwfb-run:    $(which xwfb-run 2>/dev/null || echo 'NOT FOUND')"
+    echo "  glxinfo:     $(which glxinfo 2>/dev/null || echo 'NOT FOUND')"
+    echo "  gtk3-demo:   $(which gtk3-demo 2>/dev/null || echo 'NOT FOUND')"
+    echo
+
+    # Check DRI drivers
+    echo "  DRI drivers:"
+    if [ -d /usr/lib64/dri ]; then
+        ls /usr/lib64/dri/*_dri.so 2>/dev/null | head -5 | sed 's/^/    /' || echo "    NONE FOUND"
+    else
+        echo "    /usr/lib64/dri NOT FOUND"
+    fi
+    echo
+
+    # Install dependencies first
+    install_dependencies
+
+    # =========================================================================
+    # PHASE 1: System Info & Prerequisites Check
+    # =========================================================================
+    echo -e "${BLUE}Phase 1: System Information & Prerequisites${NC}"
+    echo "========================================"
+    echo "Running: prereq/system-check"
+
+    local prereq_log="$LOGDIR/prereq_system-check.log"
+    echo "Log: $prereq_log"
+    echo -n "Result: "
+
+    # All checks go into one log file (use subshell so exit doesn't kill parent)
+    (
+        echo "========================================="
+        echo "SYSTEM INFORMATION & PREREQUISITES CHECK"
+        echo "========================================="
+        echo "Date: $(date)"
+        echo
+
+        # Hardware & System Info
+        echo "--- Architecture & Kernel ---"
+        uname -a
+        echo "Architecture: $(uname -m)"
+        echo
+
+        echo "--- CPU Information ---"
+        if [ -f /proc/cpuinfo ]; then
+            head -30 /proc/cpuinfo
+        fi
+        echo
+
+        echo "--- Memory Information ---"
+        free -h
+        echo
+
+        echo "--- PCI Devices ---"
+        if command -v lspci >/dev/null 2>&1; then
+            lspci -v
+            echo
+            echo "VGA Devices:"
+            lspci | grep -i vga || echo "No VGA devices found"
+        else
+            echo "lspci not available (expected on s390x)"
+        fi
+        echo
+
+        echo "--- Hardware Details ---"
+        if command -v lshw >/dev/null 2>&1; then
+            lshw -short 2>&1 || echo "lshw failed"
+        else
+            echo "lshw not available"
+        fi
+        echo
+
+        echo "========================================="
+        echo "PREREQUISITE CHECKS"
+        echo "========================================="
+        echo
+
+        # Check critical packages
+        prereq_failed=0
+
+        echo "--- Mesa DRI Drivers ---"
+        if rpm -q mesa-dri-drivers; then
+            echo "✓ PASS"
+        else
+            echo "✗ FAIL - mesa-dri-drivers not installed"
+            prereq_failed=1
+        fi
+        echo
+
+        echo "--- GTK3 ---"
+        if rpm -q gtk3; then
+            echo "✓ PASS"
+        else
+            echo "✗ WARN - gtk3 not installed (optional)"
+        fi
+        echo
+
+        echo "--- GTK4 ---"
+        if rpm -q gtk4; then
+            echo "✓ PASS"
+        else
+            echo "✗ FAIL - gtk4 not installed"
+            prereq_failed=1
+        fi
+        echo
+
+        echo "--- xwfb-run (headless testing) ---"
+        if which xwfb-run; then
+            echo "✓ PASS"
+        else
+            echo "✗ FAIL - xwfb-run not found"
+            prereq_failed=1
+        fi
+        echo
+
+        echo "--- Wayland Compositor ---"
+        if rpm -q mutter >/dev/null 2>&1; then
+            rpm -q mutter
+            echo "✓ PASS - mutter (GNOME) found"
+        elif rpm -q kwin >/dev/null 2>&1; then
+            rpm -q kwin
+            echo "✓ PASS - kwin (KDE) found"
+        elif rpm -q weston >/dev/null 2>&1; then
+            rpm -q weston
+            echo "✓ PASS - weston found"
+        else
+            echo "✗ FAIL - No compositor found (mutter/kwin/weston)"
+            prereq_failed=1
+        fi
+        echo
+
+        echo "--- Mesa/GL/EGL Packages ---"
+        rpm -qa | grep -E 'mesa|libGL|libEGL' | sort || echo "No Mesa packages found"
+        echo
+
+        echo "--- DRI Drivers ---"
+        if [ -d /usr/lib64/dri ]; then
+            ls -lh /usr/lib64/dri/ | grep '_dri.so$' || echo "No DRI drivers found"
+        else
+            echo "/usr/lib64/dri directory not found"
+        fi
+        echo
+
+        echo "========================================="
+        if [ $prereq_failed -eq 0 ]; then
+            echo "RESULT: All prerequisites satisfied"
+            exit 0
+        else
+            echo "RESULT: Missing critical prerequisites"
+            exit 1
+        fi
+
+    ) > "$prereq_log" 2>&1
+
+    if [ $? -eq 0 ]; then
+        echo -e "${GREEN}PASS${NC}"
+        tmt_report "prereq/system-check" "PASS" "$prereq_log"
+    else
+        echo -e "${RED}FAIL${NC}"
+        echo "  Missing prerequisites - check log for details"
+        tail -20 "$prereq_log" | sed 's/^/    /'
+        tmt_report "prereq/system-check" "FAIL" "$prereq_log"
+        OVERALL_RESULT="FAIL"
+    fi
+
+    # Submit the comprehensive log
+    tmt_submit "$prereq_log" "system-check-full.log"
+    echo
+
+    # =========================================================================
+    # PHASE 2: Library Initialization Tests
+    # =========================================================================
+    echo -e "${BLUE}Phase 2: Graphics Library Initialization${NC}"
+
+    run_test "libinit/mesa-gl" \
+        "timeout 5 bash -c 'LD_PRELOAD=/usr/lib64/libGL.so.1 /bin/true 2>&1'"
+
+    run_test "libinit/gtk3" \
+        "timeout 5 python3 -c 'import gi; gi.require_version(\"Gtk\", \"3.0\"); from gi.repository import Gtk' 2>&1"
+
+    run_test "libinit/gtk4" \
+        "timeout 5 python3 -c 'import gi; gi.require_version(\"Gtk\", \"4.0\"); from gi.repository import Gtk' 2>&1" \
+        "no"
+
+    # Check software rendering
+    ls -l /usr/lib64/ > /tmp/mesa_drivers.txt
+    if [ -f /usr/lib64/dri/swrast_dri.so ] || [ -f /usr/lib64/dri/kms_swrast_dri.so ]; then
+        echo -e "  Software renderer: ${GREEN}available${NC} (llvmpipe/swrast)"
+        tmt_report "libinit/swrast-available" "PASS" "/tmp/mesa_drivers.txt"
+    else
+        echo -e "  Software renderer: ${YELLOW}not found${NC}"
+        tmt_report "libinit/swrast-available" "WARN" "/tmp/mesa_drivers.txt"
+    fi
+
+    echo
+
+    # =========================================================================
+    # PHASE 3: Headless Graphics Stack Tests
+    # =========================================================================
+    echo -e "${BLUE}Phase 3: Headless Graphics Stack Tests${NC}"
+
+    run_test "headless/compositor-start" \
+        "timeout $TEST_TIMEOUT xwfb-run -w 2 -- true"
+
+    run_test "headless/ptyxis-help" \
+        "timeout $TEST_TIMEOUT xwfb-run -w 2 -- ptyxis --help"
+
+    # Get and report renderer info
+    local renderer_log="$LOGDIR/headless-renderer-info.log"
+    if timeout $TEST_TIMEOUT xwfb-run -w 2 -- glxinfo >"$renderer_log" 2>&1; then
+        RENDERER=$(grep "OpenGL renderer" "$renderer_log" | cut -d: -f2 | xargs)
+        VENDOR=$(grep "OpenGL vendor" "$renderer_log" | cut -d: -f2 | xargs)
+        VERSION=$(grep "OpenGL version" "$renderer_log" | cut -d: -f2 | xargs)
+
+        echo -e "  OpenGL vendor:   ${GREEN}${VENDOR}${NC}"
+        echo -e "  OpenGL renderer: ${GREEN}${RENDERER}${NC}"
+        echo -e "  OpenGL version:  ${GREEN}${VERSION}${NC}"
+
+        tmt_report "headless/renderer-info" "PASS" "$renderer_log"
+    else
+        tmt_report "headless/renderer-info" "FAIL" "$renderer_log"
+    fi
+
+    echo
+}
+
+run_phase_4() {
+    echo -e "${BLUE}========================================${NC}"
+    echo -e "${BLUE}  Phase 4: Application Rendering Tests${NC}"
+    echo -e "${BLUE}========================================${NC}"
+    echo "Architecture:  $(uname -m)"
+    echo "Log directory: $LOGDIR"
+    echo -e "${BLUE}========================================${NC}"
+    echo
+
+    # =========================================================================
+    # PHASE 4: Application Startup Tests
+    # =========================================================================
+    echo -e "${BLUE}Phase 4: Application Startup Tests${NC}"
+
+    # Check GTK renderer being used
+    echo "GTK Renderer Detection:"
+    echo "  GTK_RENDERER env: ${GTK_RENDERER:-not set (will use default)}"
+    echo "  GSK_RENDERER env: ${GSK_RENDERER:-not set}"
+    echo "  GTK_DEBUG env: ${GTK_DEBUG:-not set}"
+    echo "  Expected: GTK4 uses 'ngl' (new GL) or 'gl' renderer"
+
+    # Test GTK3 app (may not be installed on RHEL 10)
+    if which gtk3-demo >/dev/null 2>&1; then
+        run_test "app/gtk3-demo-list" \
+            "timeout $TEST_TIMEOUT xwfb-run -w 2 -- gtk3-demo --list"
+        #test some actual demo 
+        run_test "app/gtk3-demo-textscroll" \
+            "timeout $TEST_TIMEOUT xwfb-run -w 2 -- gtk3-demo --run=textscroll --autoquit"
+    else
+        echo "========================================"
+        echo "Running: app/gtk3-demo"
+        echo "Command: gtk3-demo --list"
+        echo -n "Result: "
+        echo -e "${YELLOW}SKIP${NC} (gtk3-demo not installed)"
+        tmt_report "app/gtk3-demo" "SKIP" "/dev/null"
+    fi
+
+
+    # Test GTK4
+    run_test "app/gtk4-demo-list" \
+        "timeout $TEST_TIMEOUT xwfb-run -w 2 -- gtk4-demo --list"
+
+    #Test some actual demo
+    run_test "app/gtk4-demo-textscroll" \
+        "timeout $TEST_TIMEOUT xwfb-run -w 2 -- gtk4-demo --run=textscroll --autoquit"
+
+    # Test GTK4 rendering with actual visual verification
+    local gtk4_test_script="$(dirname "$0")/gtk4_render_test.py"
+    if [ ! -f "$gtk4_test_script" ]; then
+        gtk4_test_script="./gtk4_render_test.py"
+    fi
+
+    if [ -f "$gtk4_test_script" ] && python3 -c "import gi; gi.require_version('Gtk', '4.0')" 2>/dev/null; then
+        # =====================================================================
+        # Test 1: GTK4 with default renderer
+        # =====================================================================
+        echo "========================================"
+        echo "Running: app/gtk4-render-test-default (visual verification)"
+        local gtk4_render_log="$LOGDIR/app_gtk4-render-test-default.log"
+        local gtk4_render_png="$LOGDIR/gtk4_render_test_default.png"
+        echo "Log: $gtk4_render_log"
+        echo "Output: $gtk4_render_png"
+        echo -n "Result: "
+
+        # Test with default renderer
+        if timeout $TEST_TIMEOUT xwfb-run -w 2 -- python3 "$gtk4_test_script" "$gtk4_render_png" >"$gtk4_render_log" 2>&1; then
+            # Check if PNG has good color diversity
+            if [ -f "$gtk4_render_png" ]; then
+                local colors=$(python3 -c "
+import sys
+with open('$gtk4_render_png', 'rb') as f:
+    data = f.read()
+    samples = set()
+    for i in range(100, min(len(data)-4, 2000), 10):
+        samples.add(data[i:i+4])
+    print(len(samples))
+" 2>/dev/null || echo 0)
+
+                if [ "$colors" -gt 50 ]; then
+                    echo -e "${GREEN}PASS${NC} (${colors} unique colors - rendering OK)"
+                    tmt_report "app/gtk4-render-test-default" "PASS" "$gtk4_render_log"
+                    tmt_submit "$gtk4_render_png" "gtk4-render-test-default.png"
+                else
+                    echo -e "${RED}FAIL${NC} (only ${colors} unique colors - black screen detected)"
+                    tmt_report "app/gtk4-render-test-default" "FAIL" "$gtk4_render_log"
+                    tmt_submit "$gtk4_render_png" "gtk4-render-FAILED-default.png"
+                fi
+            else
+                echo -e "${RED}FAIL${NC} (no PNG generated)"
+                tmt_report "app/gtk4-render-test-default" "FAIL" "$gtk4_render_log"
+            fi
+        else
+            echo -e "${RED}FAIL${NC} (app crashed or timed out)"
+            tmt_report "app/gtk4-render-test-default" "FAIL" "$gtk4_render_log"
+        fi
+
+        # =====================================================================
+        # Test 2: GTK4 with NGL renderer (optional/informational test)
+        # =====================================================================
+        echo "========================================"
+        echo "Running: app/gtk4-render-test-ngl (visual verification with GSK_RENDERER=ngl)"
+        echo "Note: NGL renderer test is OPTIONAL - verifies if workaround is available"
+        local gtk4_ngl_log="$LOGDIR/app_gtk4-render-test-ngl.log"
+        local gtk4_ngl_png="$LOGDIR/gtk4_render_test_ngl.png"
+        echo "Log: $gtk4_ngl_log"
+        echo "Output: $gtk4_ngl_png"
+        echo -n "Result: "
+
+        # Test with NGL renderer (non-critical - NGL may not be fully supported yet)
+        if timeout $TEST_TIMEOUT xwfb-run -w 2 -- python3 "$gtk4_test_script" "$gtk4_ngl_png" --renderer=ngl >"$gtk4_ngl_log" 2>&1; then
+            # Check if PNG has good color diversity
+            if [ -f "$gtk4_ngl_png" ]; then
+                local ngl_colors=$(python3 -c "
+import sys
+with open('$gtk4_ngl_png', 'rb') as f:
+    data = f.read()
+    samples = set()
+    for i in range(100, min(len(data)-4, 2000), 10):
+        samples.add(data[i:i+4])
+    print(len(samples))
+" 2>/dev/null || echo 0)
+
+                if [ "$ngl_colors" -gt 50 ]; then
+                    echo -e "${GREEN}PASS${NC} (${ngl_colors} unique colors - NGL renderer works!)"
+                    tmt_report "app/gtk4-render-test-ngl" "PASS" "$gtk4_ngl_log"
+                    tmt_submit "$gtk4_ngl_png" "gtk4-render-test-ngl.png"
+                else
+                    echo -e "${YELLOW}WARN${NC} (only ${ngl_colors} unique colors - NGL renderer also has issues)"
+                    tmt_report "app/gtk4-render-test-ngl" "WARN" "$gtk4_ngl_log"
+                    tmt_submit "$gtk4_ngl_png" "gtk4-render-ngl-warn.png"
+                fi
+            else
+                echo -e "${YELLOW}WARN${NC} (no PNG generated - NGL renderer failed)"
+                tmt_report "app/gtk4-render-test-ngl" "WARN" "$gtk4_ngl_log"
+            fi
+        else
+            echo -e "${YELLOW}WARN${NC} (app crashed or timed out - NGL renderer not supported/broken)"
+            tmt_report "app/gtk4-render-test-ngl" "WARN" "$gtk4_ngl_log"
+        fi
+    else
+        echo "========================================"
+        echo "Running: app/gtk4-render-test"
+        echo -n "Result: "
+        echo -e "${YELLOW}SKIP${NC} (gtk4_render_test.py or GTK4 not available)"
+        tmt_report "app/gtk4-render-test-default" "SKIP" "/dev/null"
+        tmt_report "app/gtk4-render-test-ngl" "SKIP" "/dev/null"
+    fi
+
+    if which xterm >/dev/null 2>&1; then
+        run_test "app/xterm" \
+            "timeout $TEST_TIMEOUT xwfb-run -w 2 -- xterm -e true" \
+            "no"
+    fi
+
+    if which glxgears >/dev/null 2>&1; then
+        # glxgears runs forever, so we test differently:
+        # Run for 5 seconds, check if it produces FPS output
+        echo "========================================"
+        echo "Running: app/glxgears"
+        echo "Command: xwfb-run -w 2 -- glxgears -info & sleep 25 ; killall glxgears"
+        local gears_log="$LOGDIR/app_glxgears.log"
+        echo "Log: $gears_log"
+        echo -n "Result: "
+
+        # Run glxgears for 5 seconds with kill timeout
+        xwfb-run -w 2 -- glxgears -info >"$gears_log" 2>&1 &
+        sleep 25
+        killall glxgears
+        local exit_code=$?
+
+        # Wait a moment for cleanup
+        sleep 1
+
+        # Check if we got FPS output (means it rendered successfully)
+        if grep -q "frames in.*seconds.*FPS" "$gears_log"; then
+            echo -e "${GREEN}PASS${NC} (rendered frames successfully)"
+            if [ "$VERBOSE" == "1" ]; then
+                echo "  GL Renderer:"
+                grep "GL_RENDERER" "$gears_log" | sed 's/^/    /'
+                echo "  Performance:"
+                grep "frames in.*seconds.*FPS" "$gears_log" | head -3 | sed 's/^/    /'
+            fi
+            tmt_report "app/glxgears" "PASS" "$gears_log"
+        else
+            echo -e "${YELLOW}WARN${NC} (no FPS output, exit code: $exit_code)"
+            if [ "$VERBOSE" == "1" ]; then
+                echo "  Log output:"
+                tail -10 "$gears_log" | sed 's/^/    /'
+            fi
+            tmt_report "app/glxgears" "WARN" "$gears_log"
+        fi
+
+        # Cleanup any remaining processes
+        killall -9 glxgears mutter dbus-run-session 2>/dev/null || true
+    fi
+
+    echo
+}
+
+# =============================================================================
+# Main Test Execution
+# =============================================================================
+
+main() {
+    # Parse command-line arguments
+    local RUN_PHASES="all"  # Default: run all phases
+
+    while [[ $# -gt 0 ]]; do
+        case $1 in
+            --phase=*)
+                RUN_PHASES="${1#*=}"
+                shift
+                ;;
+            --help)
+                echo "Usage: $0 [--phase=1-3|4|all]"
+                echo "  --phase=1-3  Run only infrastructure tests (Phases 1-3)"
+                echo "  --phase=4    Run only application rendering tests (Phase 4)"
+                echo "  --phase=all  Run all phases (default)"
+                exit 0
+                ;;
+            *)
+                echo "Unknown option: $1"
+                echo "Use --help for usage information"
+                exit 1
+                ;;
+        esac
+    done
+
+    echo -e "${BLUE}========================================${NC}"
+    echo -e "${BLUE}  Graphics Stack Smoke Test${NC}"
+    echo -e "${BLUE}========================================${NC}"
+    echo "Run mode: $RUN_PHASES"
+    echo "Architecture: $(uname -m)"
+    echo
+
+    # Run requested phases
+    case "$RUN_PHASES" in
+        "1-3")
+            run_phases_1_to_3
+            ;;
+        "4")
+            run_phase_4
+            ;;
+        "all")
+            run_phases_1_to_3
+            run_phase_4
+            ;;
+        *)
+            echo "ERROR: Invalid phase specification: $RUN_PHASES"
+            echo "Valid options: 1-3, 4, all"
+            exit 1
+            ;;
+    esac
+
+    # =========================================================================
+    # Results Summary
+    # =========================================================================
+    echo -e "${BLUE}========================================${NC}"
+    echo -e "${BLUE}  Test Results Summary${NC}"
+    echo -e "${BLUE}========================================${NC}"
+
+    # Show all logs
+    echo "Generated logs:"
+    ls -lh "$LOGDIR" | tail -n +2 | awk '{printf "  %s  %s\n", $9, $5}'
+    echo
+
+    if [ "$OVERALL_RESULT" == "PASS" ]; then
+        echo -e "${GREEN}✓ ALL CRITICAL TESTS PASSED${NC}"
+        echo -e "${BLUE}========================================${NC}"
+        echo "Graphics stack is functional on $(uname -m)"
+        echo "Logs saved to: $LOGDIR"
+        echo "Master log: $LOGDIR/00-master-test.log"
+
+        # Submit master log and any screenshots
+        echo
+        echo "Submitting artifacts to TMT..."
+        tmt_submit "$LOGDIR/00-master-test.log" "master-test.log"
+
+        # Submit any PNG screenshots as visual evidence
+        for png in "$LOGDIR"/*.png; do
+            if [ -f "$png" ]; then
+                tmt_submit "$png" "$(basename $png)"
+            fi
+        done
+
+        # Final overall report
+        tmt_report "graphics-smoke-test" "PASS" "$LOGDIR/00-master-test.log"
+        exit 0
+    else
+        echo -e "${RED}✗ ONE OR MORE CRITICAL TESTS FAILED${NC}"
+        echo -e "${BLUE}========================================${NC}"
+        echo "Graphics stack validation failed"
+        echo "Logs saved to: $LOGDIR"
+        echo "Master log: $LOGDIR/00-master-test.log"
+        echo
+
+        # Show detailed failure information
+        echo -e "${RED}Failed Tests:${NC}"
+        if ls "$LOGDIR"/*.log >/dev/null 2>&1; then
+            for logfile in "$LOGDIR"/*.log; do
+                testname=$(basename "$logfile" .log)
+                # Check if it's a failed test (non-zero exit or error keywords)
+                if grep -qi "error\|fail\|cannot\|unable" "$logfile" 2>/dev/null; then
+                    echo -e "  ${RED}✗${NC} $testname"
+                    echo "    Log: $logfile"
+                    echo "    Last 10 lines:"
+                    tail -10 "$logfile" | sed 's/^/      /'
+                    echo
+                fi
+            done
+        fi
+
+        # Submit master log and all artifacts for debugging
+        echo
+        echo "Submitting artifacts to TMT..."
+        tmt_submit "$LOGDIR/00-master-test.log" "master-test.log"
+
+        # Submit all PNG screenshots as evidence of failure
+        for png in "$LOGDIR"/*.png; do
+            if [ -f "$png" ]; then
+                tmt_submit "$png" "$(basename $png)"
+            fi
+        done
+
+        # Submit failed test logs
+        for log in "$LOGDIR"/*.log; do
+            if [ -f "$log" ] && grep -qi "error\|fail" "$log" 2>/dev/null; then
+                tmt_submit "$log" "$(basename $log)"
+            fi
+        done
+
+        # Final overall report
+        tmt_report "graphics-smoke-test" "FAIL" "$LOGDIR/00-master-test.log"
+        exit 1
+    fi
+}
+
+# =============================================================================
+# Script Entry Point
+# =============================================================================
+
+# Pass all command-line arguments to main
+main "$@"
diff --git a/tests/gtk4_render_test.py b/tests/gtk4_render_test.py
new file mode 100755
index 0000000..b51ee8e
--- /dev/null
+++ b/tests/gtk4_render_test.py
@@ -0,0 +1,146 @@
+#!/usr/bin/env python3
+"""
+GTK4 Rendering Test - Verifies actual rendering by drawing and saving
+Tests the s390x Mesa bug where GTK apps show black screens
+"""
+
+import sys
+import os
+
+# Parse renderer argument BEFORE importing GTK
+# GSK_RENDERER must be set before GTK initializes
+renderer = None
+output_file = None
+
+for i, arg in enumerate(sys.argv[1:], 1):
+    if arg.startswith('--renderer='):
+        renderer = arg.split('=', 1)[1]
+    elif not arg.startswith('--'):
+        output_file = arg
+
+if renderer:
+    os.environ['GSK_RENDERER'] = renderer
+    print(f"Setting GSK_RENDERER={renderer} before GTK import")
+
+#Set debug to print rear renderer of app
+os.environ['GSK_DEBUG'] = "renderer"
+
+# Now import GTK (after setting environment)
+import gi
+gi.require_version('Gtk', '4.0')
+from gi.repository import Gtk, GLib
+import cairo
+
+class RenderTestApp(Gtk.Application):
+    def __init__(self, output_file):
+        super().__init__(application_id='org.test.gtk4render')
+        self.output_file = output_file
+        self.rendered = False
+        self.drawing_area = None
+
+    def do_activate(self):
+        window = Gtk.ApplicationWindow(application=self)
+        window.set_title("GTK4 Rendering Test")
+        window.set_default_size(400, 300)
+
+        self.drawing_area = Gtk.DrawingArea()
+        self.drawing_area.set_draw_func(self.draw_callback)
+
+        window.set_child(self.drawing_area)
+        window.present()
+
+        # Wait for rendering, then save and quit
+        GLib.timeout_add(2000, self.save_and_quit)
+
+    def draw_callback(self, area, cr, width, height):
+        """Draw colorful pattern to prove rendering works"""
+        # Red rectangle
+        cr.set_source_rgb(1.0, 0.0, 0.0)
+        cr.rectangle(10, 10, 100, 100)
+        cr.fill()
+
+        # Green rectangle
+        cr.set_source_rgb(0.0, 1.0, 0.0)
+        cr.rectangle(130, 10, 100, 100)
+        cr.fill()
+
+        # Blue rectangle
+        cr.set_source_rgb(0.0, 0.0, 1.0)
+        cr.rectangle(250, 10, 100, 100)
+        cr.fill()
+
+        # Yellow circle
+        cr.set_source_rgb(1.0, 1.0, 0.0)
+        cr.arc(200, 200, 50, 0, 2 * 3.14159)
+        cr.fill()
+
+        print(f"Draw callback called - rendering {width}x{height} surface")
+        self.rendered = True
+
+    def save_and_quit(self):
+        """Save the rendered surface to PNG and exit"""
+        if not self.rendered:
+            print("WARNING: Draw function not called yet")
+            print("RESULT: WARN - Rendering may not have occurred")
+            self.quit()
+            return False
+
+        try:
+            # Get the window and widget dimensions
+            width = self.drawing_area.get_width()
+            height = self.drawing_area.get_height()
+
+            print(f"Creating Cairo surface {width}x{height}")
+
+            # Create a Cairo image surface
+            surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, width, height)
+            cr = cairo.Context(surface)
+
+            # Re-render to this surface
+            self.draw_callback(None, cr, width, height)
+
+            # Save to PNG
+            surface.write_to_png(self.output_file)
+
+            # Check file was created and has reasonable size
+            if os.path.exists(self.output_file):
+                file_size = os.path.getsize(self.output_file)
+                print(f"SUCCESS: Saved rendering to {self.output_file} ({file_size} bytes)")
+
+                if file_size > 1000:
+                    print("RESULT: PASS - Rendering verified")
+                else:
+                    print(f"RESULT: FAIL - PNG file too small ({file_size} bytes)")
+            else:
+                print(f"RESULT: FAIL - Failed to create {self.output_file}")
+
+        except Exception as e:
+            print(f"ERROR: {e}")
+            import traceback
+            traceback.print_exc()
+            print("RESULT: FAIL - Exception during rendering")
+
+        self.quit()
+        return False
+
+
+def main():
+    global output_file
+
+    if not output_file:
+        print(f"Usage: {sys.argv[0]} <output.png> [--renderer=ngl|gl|cairo|vulkan]")
+        print(f"  --renderer: GSK renderer to use (default: auto-detect)")
+        sys.exit(1)
+
+    print(f"GTK4 Rendering Test - will save to {output_file}")
+    print(f"GSK_RENDERER: {os.environ.get('GSK_RENDERER', 'not set (auto-detect)')}")
+    print(f"GTK_RENDERER: {os.environ.get('GTK_RENDERER', 'not set')}")
+
+    app = RenderTestApp(output_file)
+    exit_status = app.run(None)
+
+    sys.exit(exit_status)
+
+
+if __name__ == '__main__':
+    main()