Add repro case showing that extra-sources in OPAM files don't work
#27429
| Job | Run time |
|---|---|
| 2m 32s | |
| 2m 9s | |
| 55s | |
| 9m 37s | |
| 8m 22s | |
| 14m 30s | |
| 9m 0s | |
| 10m 3s | |
| 38s | |
| 14m 47s | |
| 10m 17s | |
| 2m 23s | |
| 2m 47s | |
| 5m 39s | |
| 3m 23s | |
| 6m 13s | |
| 5m 30s | |
| 4m 53s | |
| 2m 0s | |
| 4m 56s | |
| 2m 1s | |
| 1m 57s | |
| 5m 28s | |
| 4m 12s | |
| 2h 14m 12s |