- Exclude unsupported combinations
- Include custom combinations
- Control failure behavior (
fail-fast) - Limit parallel jobs (
max-parallel)

1. Excluding Specific Combinations
To prevent certain OS–image pairs (like Alpine on Windows) from running, use theexclude keyword under strategy.matrix:
windows-latest + alpine job, reducing the total from six to five.
Excluding unsupported combinations helps save build minutes and avoids predictable failures.
2. Including Additional Combinations
Useinclude to add custom pairs beyond the default matrix. For instance, to run amd64/alpine only on Ubuntu 20.04:
amd64/alpine builds only on Ubuntu 20.04, while still excluding Alpine on Windows.
3. Controlling Failure Behavior and Parallelism
By default,fail-fast: true cancels all remaining jobs if one fails. You can disable this and control concurrency:

amd64/alpine is included only on Ubuntu 20.04:
