build.res: allow dir="-" when requesting resources with subsignals.
#3517
| Job | Run time |
|---|---|
| 41s | |
| 36s | |
| 40s | |
| 37s | |
| 44s | |
| 2m 27s | |
| 2m 40s | |
| 2m 7s | |
| 2m 38s | |
| 3m 20s | |
| 5m 4s | |
| 4m 50s | |
| 5m 10s | |
| 3m 10s | |
| 15s | |
| 0s | |
| 1s | |
| 5s | |
| 42s | |
| 0s | |
| 35m 47s |