The error 'Unknown command line options: --vt 1' means you don't have (or aren't using?) the mesa-kms graphics driver needed to interpret that option. I don't know if the mir-server snap has correctly provided this.
The error 'Unknown command line options: --vt 1' means you don't have (or aren't using?) the mesa-kms graphics driver needed to interpret that option. I don't know if the mir-server snap has correctly provided this.