Download Mesa from Qt's CDN

compile_all.py

@@ -445,6 +445,28 @@ def _install_python_requirements(self, requirements):
                 print(e.output.decode("utf-8", errors="replace"))
             exit(1)
 
+    def build_opengl32sw(self, _: None):
+        """Copy Mesa software OpenGL DLL into the LibPack on x64. On ARM64 the DLL is
+        unavailable from Qt's CDN. Does not actually build anything, just copies it."""
+        target = os.path.join(self.install_dir, "bin", "opengl32sw.dll")
+        if self.skip_existing and os.path.exists(target):
+            print("  opengl32sw.dll already in the LibPack, not re-copying")
+            return
+        if platform.machine() == "ARM64":
+            print("  NOTE: opengl32sw.dll is not available for Windows on ARM64 - Skipping")
+            return
+        matches = list(pathlib.Path(os.getcwd()).rglob("opengl32sw.dll"))
+        if not matches:
+            print(
+                f"ERROR: opengl32sw.dll not found under {os.getcwd()}. "
+                "The download or 7z extraction probably failed; check the URL "
+                "in config.json and retry."
+            )
+            exit(1)
+        os.makedirs(os.path.dirname(target), exist_ok=True)
+        shutil.copyfile(str(matches[0]), target)
+        print(f"  Copied {matches[0]} to {target}")
+
     def build_qt(self, options: dict):
         """Build Qt from source. Always builds qtbase, qtsvg, qtdeclarative, and qttools
         against the LibPack's own zlib and libpng."""

config.json

@@ -90,6 +90,11 @@
             "git-ref": "v6.11.0",
             "fallback-build-dir": "G:\\temp"
         },
+        {
+            "name": "opengl32sw",
+            "url-x64": "https://download.qt.io/online/qtsdkrepository/windows_x86/desktop/qt6_6110/qt6_6110_msvc2022_64/qt.qt6.6110.win64_msvc2022_64/6.11.0-0-202603180535opengl32sw-64-mesa_11_2_2-signed_sha256.7z",
+            "note": "Mesa-based software OpenGL fallback shipped by The Qt Company alongside their precompiled Qt binaries. Required at runtime on systems whose GPU or driver only exposes OpenGL 1.x (common on Windows VMs without GPU passthrough). Qt's from-source build does not produce this DLL, so the LibPack pulls the precompiled file directly from Qt's online installer CDN. The exact archive filename embeds a build timestamp and changes when Qt rebuilds the package; if the URL stops resolving, locate the current archive under the same Updates.xml path. No equivalent prebuilt is published for Windows on ARM64; ARM64 builds skip this entry entirely (see build_opengl32sw)."
+        },
         {
             "name":"bzip2",
             "git-repo":"https://gitlab.com/bzip2/bzip2.git",

create_libpack.py

@@ -135,7 +135,7 @@ def fetch_remote_data(config: dict, skip_existing: bool = False):
             download(item["name"], item["url"])
         elif "url-ARM64" in item and platform.machine() == "ARM64":
             download(item["name"], item["url-ARM64"])
-        elif "url-x64" in item:
+        elif "url-x64" in item and platform.machine() == "AMD64":
             download(item["name"], item["url-x64"])
         else:
             # Just make the directory, presumably later code will know what to do