Currently supported architectures for multi-arch runs: amd64 and arm64.
On clusters where nodes have different CPU architectures, you must pass --cpu-arch to select the architecture for the run. Use a single value (e.g. --cpu-arch=amd64) or, for tests marked with multiarch, a comma-separated list (e.g. --cpu-arch=amd64,arm64). Use the config file tests/global_config_multiarch.py and the multiarch marker for tests that run across multiple architectures. Do not pass --cpu-arch on homogeneous clusters.
uv run pytest --tc-file=tests/global_config_multiarch.py --cpu-arch=amd64 ...*_os_matrix variables are not created for multi-arch runs (when --cpu-arch contains multiple architectures, e.g. --cpu-arch=amd64,arm64).