Currently, there are problems with the way patterns are matched for
the task ID when calling task exec. Specifically, it doesn't follow the
semantics indicated in the help string for (1) matching regular
expressions and (2) matching any substring within the ID, not just the
prefix of the ID.
The reason we do not adhere to these semantics is because we are
trying to match the exact semantics of docker exec, which only allows
prefix matching, not arbitrary regex or 'contains()' like semantics for
pattern matching the ID.
We should decide how to remedy this.