ci: make smoke runner headless-safe and add explicit EEVEE-id assertion

Runner fix: GPU-less GitHub runners abort EEVEE GPU rendering with a C-level core dump (libEGL.so.1 missing, exit 134) that Python try/except cannot catch. Install Blender's GL runtime libs + xvfb and run Blender under xvfb-run; render the non-black frame with Cycles (CPU) instead of EEVEE. Gate fix: keep a dedicated, frame-independent EEVEE engine-id assertion (eevee-engine-id-assigns) that compares the helper's id against the version-expected id (BLENDER_EEVEE on 5.x, BLENDER_EEVEE_NEXT on 4.2-4.5) so the polarity bug (CRITICAL #1) stays guarded even though rendering is Cycles. Verified: green on 5.1.1 and 4.5.10; re-inverting get_eevee_engine_id() makes eevee-engine-id-assigns FAIL (exit 1) on both builds (enum not found).

Signed-off-by: fOuttaMyPaint <TMhospitalitystrategies@gmail.com>

Author: TMHSDigital

.github/workflows/blender-smoke.yml

@@ -34,6 +34,16 @@ jobs:
     steps:
       - uses: actions/checkout@v6
 
+      - name: Install Blender runtime libraries
+        run: |
+          set -euo pipefail
+          sudo apt-get update
+          # Blender needs these shared libs even in --background (GPU/GL module init);
+          # xvfb provides a virtual display so GL/EGL init does not abort the process.
+          sudo apt-get install -y --no-install-recommends \
+            xvfb libgl1 libegl1 libxrender1 libxxf86vm1 libxfixes3 libxi6 \
+            libxkbcommon0 libsm6 libice6
+
       - name: Resolve and download Blender ${{ matrix.series }}
         run: |
           set -euo pipefail
@@ -72,17 +82,17 @@ jobs:
         run: |
           set -euo pipefail
           mkdir -p "$RUNNER_TEMP/out"
-          "$BLENDER" --background --python tests/smoke/run_smoke.py -- "$RUNNER_TEMP/out"
+          xvfb-run -a "$BLENDER" --background --python tests/smoke/run_smoke.py -- "$RUNNER_TEMP/out"
 
       - name: Build template input scene
         run: |
           set -euo pipefail
-          "$BLENDER" --background --python tests/smoke/make_input.py -- "$RUNNER_TEMP/out/input.blend"
+          xvfb-run -a "$BLENDER" --background --python tests/smoke/make_input.py -- "$RUNNER_TEMP/out/input.blend"
 
       - name: Headless glTF template runs (exit 0, .glb produced)
         run: |
           set -euo pipefail
-          "$BLENDER" --background "$RUNNER_TEMP/out/input.blend" \
+          xvfb-run -a "$BLENDER" --background "$RUNNER_TEMP/out/input.blend" \
             --python tests/smoke/tmpl_gltf.py -- \
             --output "$RUNNER_TEMP/out/out.glb" --apply-modifier SUBSURF
           test -s "$RUNNER_TEMP/out/out.glb" || { echo "::error::glTF output missing/empty"; exit 1; }
@@ -91,7 +101,7 @@ jobs:
       - name: Headless template no-mesh path returns exit 2
         run: |
           set +e
-          "$BLENDER" --background "$RUNNER_TEMP/out/empty.blend" \
+          xvfb-run -a "$BLENDER" --background "$RUNNER_TEMP/out/empty.blend" \
             --python tests/smoke/tmpl_gltf.py -- --output "$RUNNER_TEMP/out/none.glb"
           code=$?
           set -e
@@ -103,7 +113,7 @@ jobs:
           set -euo pipefail
           # Cycles (CPU) so this is reliable on GPU-less runners; the EEVEE-id regression
           # itself is gated in run_smoke.py via engine assignment.
-          "$BLENDER" --background "$RUNNER_TEMP/out/input.blend" \
+          xvfb-run -a "$BLENDER" --background "$RUNNER_TEMP/out/input.blend" \
             --python tests/smoke/tmpl_render.py -- \
             --output "$RUNNER_TEMP/out/render.png" --engine CYCLES
           test -s "$RUNNER_TEMP/out/render.png" || { echo "::error::render PNG missing/empty"; exit 1; }

tests/smoke/run_smoke.py

@@ -108,31 +108,31 @@ def smoke_eevee():
     cam = bpy.data.objects.new("cam", bpy.data.cameras.new("cam")); bpy.context.collection.objects.link(cam)
     cam.location = (0,0,10); bpy.context.scene.camera = cam
     sc = bpy.context.scene
-    # the EEVEE-id regression guard: assigning the version-correct id must succeed
+    # THE EEVEE-id polarity guard (CRITICAL #1). Independent of any rendered frame, so it
+    # cannot flake on the GL/EGL context. `eid` is the repo helper's output (under test);
+    # `expected` is computed here from the version, so an inverted helper is caught.
     eid = get_eevee_engine_id()
+    expected = 'BLENDER_EEVEE' if bpy.app.version >= (5, 0, 0) else 'BLENDER_EEVEE_NEXT'
+    assigned = True; err = ""
     try:
         sc.render.engine = eid
     except Exception as e:
-        require("eevee-id-assign", False, f"assigning '{eid}' raised {type(e).__name__}: {e}")
-    require("eevee-id-assign", sc.render.engine == eid, f"engine id '{eid}' valid on this build")
+        assigned = False; err = f"{type(e).__name__}: {e}"
+    require("eevee-engine-id-assigns",
+            assigned and sc.render.engine == expected,
+            f"helper returned '{eid}'; engine='{sc.render.engine if assigned else 'UNASSIGNED('+err+')'}' expected='{expected}'")
+    # Render the non-black frame with Cycles (CPU): reliable on GPU-less headless runners,
+    # where an EEVEE GPU render aborts the process (no EGL). The EEVEE-id regression itself
+    # is already gated by the assignment above; EEVEE *rendering* is not exercised here.
+    sc.render.engine = 'CYCLES'
+    try: sc.cycles.samples = 4
+    except Exception: pass
     sc.render.resolution_x = 16; sc.render.resolution_y = 16; sc.render.image_settings.file_format = 'PNG'
     png = os.path.join(OUT, f"smoke_render_{V[0]}{V[1]}.png"); sc.render.filepath = png
-    # try EEVEE render; if the headless runner has no GPU and it raises, fall back to Cycles (CPU)
-    used = sc.render.engine
-    try:
-        try: sc.eevee.taa_render_samples = 4
-        except Exception: pass
-        bpy.ops.render.render(write_still=True)
-        if not os.path.exists(png): raise RuntimeError("no PNG written")
-    except Exception as e:
-        print(f"  (EEVEE render unavailable headless: {type(e).__name__}; falling back to CYCLES)")
-        sc.render.engine = 'CYCLES'; used = 'CYCLES'
-        try: sc.cycles.samples = 4
-        except Exception: pass
-        bpy.ops.render.render(write_still=True)
-    require("eevee-render-file", os.path.exists(png) and os.path.getsize(png) > 0, f"render PNG written by {used}")
+    bpy.ops.render.render(write_still=True)
+    require("render-file", os.path.exists(png) and os.path.getsize(png) > 0, "1-frame render PNG written (Cycles CPU)")
     img = bpy.data.images.load(png); px = list(img.pixels); mx = max(px) if px else 0.0
-    require("eevee-render-nonblack", mx > 0.05, f"max pixel {round(mx,3)} > 0.05 (engine used: {used})")
+    require("render-nonblack", mx > 0.05, f"max pixel {round(mx,3)} > 0.05 (emissive material renders bright)")
 
 # ---------- slotted actions: correct branch + legacy behaviour ----------
 def smoke_slotted():