how to filter github action matrices (matrix fails to render as well)

Badge NO FILTER

[](https://github.com/mgood7123/prebuilder/actions)

`[](https://github.com/mgood7123/prebuilder/actions)`

Badge FILTERED

[](https://github.com/mgood7123/prebuilder/actions)

`[](https://github.com/mgood7123/prebuilder/actions)`

why does this have `Waiting For A Run` even though the workflow has succeeded?

also why does the matrix fail to render?

cmake.yaml:

```yaml
name: CMake

on:
push:
branches: [ main ]

concurrency:
group: build
cancel-in-progress: true

env:
# Customize the CMake build type here (Release, Debug, RelWithDebInfo, etc.)
BUILD_TYPE: Debug

jobs:
build:
runs-on: ${{ matrix.os }}
permissions:
contents: write
strategy:
fail-fast: false
max-parallel: 1
matrix:
include:

- os: ubuntu-latest
extension: so

- os: macOS-latest
extension: dylib

- os: windows-latest
extension: dll

defaults:
run:
shell: bash

steps:
- uses: actions/checkout@v2

# ommited
```