Arvados

This keep reference is invalid, but a-c-r validation doesn't catch it:

keep:/ffffffffffffffffffffffffffffffff+999/ABC123.fastq.gz

In addition, this is an invalid mount request, and the API server doesn't catch it either:

"mounts": {
  "keep:/ffffffffffffffffffffffffffffffff+999": { ... }
}

As a result, the container gets stuck in a start-fail loop. Issue #11561 (included in Arvados 1.4) limits the number of retries, but earlier versions would loop forever.