Pin PNNX to avoid PNNX==20240410 bug (#9953)

Co-authored-by: UltralyticsAssistant <web@ultralytics.com>

.github/workflows/ci.yaml

@@ -123,7 +123,7 @@ jobs:
         run: coverage run -a --source=ultralytics -m ultralytics.cfg.__init__ benchmark model='path with spaces/yolov8s-worldv2.pt' imgsz=160 verbose=0.318
       - name: Benchmark SegmentationModel
         shell: bash
-        run: coverage run -a --source=ultralytics -m ultralytics.cfg.__init__ benchmark model='path with spaces/${{ matrix.model }}-seg.pt' imgsz=160 verbose=0.281
+        run: coverage run -a --source=ultralytics -m ultralytics.cfg.__init__ benchmark model='path with spaces/${{ matrix.model }}-seg.pt' imgsz=160 verbose=0.280
       - name: Benchmark ClassificationModel
         shell: bash
         run: coverage run -a --source=ultralytics -m ultralytics.cfg.__init__ benchmark model='path with spaces/${{ matrix.model }}-cls.pt' imgsz=160 verbose=0.166

ultralytics/engine/exporter.py

@@ -529,12 +529,16 @@ class Exporter:
                 f"or in {ROOT}. See PNNX repo for full installation instructions."
             )
             system = "macos" if MACOS else "windows" if WINDOWS else "linux-aarch64" if ARM64 else "linux"
-            try:
-                _, assets = get_github_assets(repo="pnnx/pnnx", retry=True)
-                url = [x for x in assets if f"{system}.zip" in x][0]
-            except Exception as e:
-                url = f"https://github.com/pnnx/pnnx/releases/download/20240226/pnnx-20240226-{system}.zip"
-                LOGGER.warning(f"{prefix} WARNING ⚠️ PNNX GitHub assets not found: {e}, using default {url}")
+
+            # PNNX link fixed at 20240226 due to bug in 20240410
+            # try:
+            #     _, assets = get_github_assets(repo="pnnx/pnnx", retry=True)
+            #     url = [x for x in assets if f"{system}.zip" in x][0]
+            # except Exception as e:
+            #     url = f"https://github.com/pnnx/pnnx/releases/download/20240226/pnnx-20240226-{system}.zip"
+            #     LOGGER.warning(f"{prefix} WARNING ⚠️ PNNX GitHub assets not found: {e}, using default {url}")
+
+            url = f"https://github.com/pnnx/pnnx/releases/download/20240226/pnnx-20240226-{system}.zip"
             asset = attempt_download_asset(url, repo="pnnx/pnnx", release="latest")
             if check_is_path_safe(Path.cwd(), asset):  # avoid path traversal security vulnerability
                 unzip_dir = Path(asset).with_suffix("")