Fix readToEnd being slow for child processes with large output (#354)
#1085
| Job | Run time |
|---|---|
| 11s | |
| 5s | |
| 5m 36s | |
| 5m 49s | |
| 2m 44s | |
| 2m 27s | |
| 3m 7s | |
| 2m 45s | |
| 22m 44s |