node:
    mac: v8.9.4
        recently updated to: 8.12.0 (sudo n 8.12.0)
            tried v10.13.0 (sudo n lts) but it generated error: warning You are using Node "10.13.0" which is not supported and may encounter bugs or unexpected behavior. Yarn supports the following semver range: "^4.8.0 || ^5.7.0 || ^6.2.2 || ^8.0.0"
            so I've checked table: https://nodejs.org/en/download/releases/ and previous lts was:
                8.12.0

    prod ubuntu: v8.9.4