src/developer/ffx/data/config.json

{
    "log": {
        "dir": [
            "$FFX_LOG_DIR",
            "$CACHE/logs"
        ],
        "enabled": [
            "$FFX_LOG_ENABLED",
            true
        ],
        "level": "Debug",
        "rotations": 5,
        "rotate_size": 104857600
    },
    "proxy": {
        "timeout_secs": 10.0
    }
}