By: Tom Sydney Kerckhove <syd@cs-syd.eu>
Return a single derivation from mutationCheck Simplify mutationCheck to return either the check or the report derivation directly instead of an attrset, and expose the report as a passthru on the check derivation so callers can still reach it.
| Time to Start | Worker time | Duration | Time to finish | Idle | |
| Config | 3s | 2s | 2s | 6s | 3s |
| Eval | 6s | 39s | 39s | 46s | 0s |
| Build | 9s | 17m19s | 16m36s | 16m46s | 0s |
| Suite | 3s | 18m01s | 16m43s | 16m46s | 3s |