Try fixing the matrix creator in the github runner.

.github/workflows/build.yml

@@ -4,45 +4,30 @@ on:
   workflow_dispatch:
 
 jobs:
+  define-matrix:
+    runs-on: ubuntu-latest
+
+    outputs:
+      matrix-include: ${{ steps.make_matrix.outputs.include }}
+
+    steps:
+      - name: Set up Python 3.x
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.x"
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Load Matrix
+        id: make_matrix
+        run: |
+          echo 'include='$(python3 make_github_runner_config.py) >> "$GITHUB_OUTPUT"
+
   build:
+    needs: define-matrix
     strategy:
       fail-fast: false
       matrix:
-        # Double float precision builds are not needed by default;
-        # whoever needs them can recompile, but it would blow up our release zip to include them.
-        float-precision: [single]
-        build-target-type: [template_debug, template_release]
-        include:
-          - platform: linux
-            arch: x86_64
-            os: ubuntu-20.04
-          - platform: windows
-            arch: x86_32
-            os: windows-latest
-          - platform: windows
-            arch: x86_64
-            os: windows-latest
-          - platform: macos
-            arch: universal
-            os: macos-latest
-          - platform: android
-            arch: arm64
-            os: ubuntu-20.04
-          - platform: android
-            arch: arm32
-            os: ubuntu-20.04
-          - platform: android
-            arch: x86_64
-            os: ubuntu-20.04
-          - platform: android
-            arch: x86_32
-            os: ubuntu-20.04
-          - platform: ios
-            arch: arm64
-            os: macos-latest
-          - platform: web
-            arch: wasm32
-            os: ubuntu-20.04
+        include: ${{ fromJSON(needs.define-matrix.outputs.matrix-include) }}
 
     runs-on: ${{ matrix.os }}
     steps:

make_github_runner_config.py

@@ -0,0 +1,74 @@
+import json
+
+# Ah, imagine if github matrix interpreters could just have this little function...
+def unroll_config(cfg: dict):
+    configs = [{}]
+
+    for key, value in cfg.items():
+        if key == "combine":
+            # List of configs
+            configs = [
+                {**cfg_base, **cfg_combine}
+                for cfg_base in configs
+                for combine_template in cfg["combine"]
+                for cfg_combine in unroll_config(combine_template)
+            ]
+        elif isinstance(value, list):
+            # Value list
+            configs = [
+                {**config, key: value}
+                for value in value
+                for config in configs
+            ]
+        else:
+            # Single value
+            configs = [
+                {**config, key: value}
+                for config in configs
+            ]
+
+    return configs
+
+
+config = dict(
+    # Could build with double, but that would double (hah) our build count.
+    # Doubles are custom builds, so let somebody else do that.
+    float_precision=["single"],
+    build_target_type=["template_debug", "template_release"],
+    combine=[
+        dict(
+            platform="macos",
+            os="macos-latest",
+            arch="universal",
+        ),
+        dict(
+            platform="ios",
+            os="macos-latest",
+            arch="arm64",
+        ),
+        dict(
+            platform="linux",
+            os="ubuntu-20.04",
+            arch=["x86_64", "arm64", "rv64"],
+        ),
+        dict(
+            platform="windows",
+            os="windows-latest",
+            arch=["x86_32", "x86_64"],
+        ),
+        dict(
+            platform="android",
+            os="ubuntu-20.04",
+            arch=["x86_64", "arm64"],
+        ),
+        dict(
+            platform="web",
+            os="ubuntu-20.04",
+            arch="wasm32",
+        ),
+    ]
+)
+
+includes = unroll_config(config)
+
+print(json.dumps(includes))