Add nix.linux-builder.systems option to set corresponding nix.buildMachines.*.systems option
#1159
| Job | Run time |
|---|---|
| 3m 34s | |
| 3m 36s | |
| 7m 2s | |
| 2m 41s | |
| 6m 24s | |
| 3m 47s | |
| 27m 4s |