How to parse moby.buildkit.trace ?

[punkpeye]

{
  event: {
    id: 'moby.buildkit.trace',
    aux: 'CsIBCkdzaGEyNTY6OTRmYzk2ZmMxYTZjZDQ2ZmRlNjFhNmZiZDU4ODE5ZmI3NjJmYzY2MWZjYTcyNmUzMmUwOGZmYmJmZmE5ZjA3ZhJHc2hhMjU2OjdkMjg5NzI2NTQ2MjhhZGZlM2RkMGMwMDMzN2ExMDkyOGI1NjRkMDM4MzA5NWEzNDNkZDNjYzZlMDY0MDRhYjQaEls3LzddIFdPUktESVIgL2FwcCoMCMmf/70GELy/p9sCMgwIyZ//vQYQ0rji4AI='
  }
}

How do I convert this to something I can read?

[punkpeye]

It is obviously base64 encoded, but not clear beyond that.