schema.json

{
  "type": "object",
  "properties": {
    "homepage": {
      "type": "string"
    },
    "versions": {
      "type": "object",
      "patternProperties": {
        "^\\d+\\.\\d+\\.\\d+(?:\\-[0-9A-Za-z-\\.]+)?(?:\\+[0-9A-Za-z-\\.]+)?$": {
          "oneOf": [
            {
              "$ref": "#/definitions/version"
            },
            {
              "type": "array",
              "items": {
                "$ref": "#/definitions/version"
              }
            }
          ]
        }
      },
      "additionalProperties": false
    }
  },
  "definitions": {
    "version": {
      "oneOf": [
        {
          "type": "string"
        },
        {
          "type": "object",
          "properties": {
            "compiler": {
              "type": "string",
              "pattern": "^\\d+\\.\\d+\\.\\d+$"
            },
            "location": {
              "type": "string"
            },
            "description": {
              "type": "string"
            }
          },
          "additionalProperties": false
        }
      ]
    }
  },
  "additionalProperties": false
}