{
    "blobs": [],
    "trees": {},
    "actions": {
        "write_to_file": {
            "output": ["out"],
            "command": [
                "/bin/sh",
                "-c",
                "set -e\necho -n ${MYCONTENT} > out"
            ],
            "env": {
                "MYCONTENT": "content from environment variable",
                "UNUSED_VAR": "nothing important"
            }
        }
    }
}