Problem: hydra machine: Running out of memory

[clacke]

hydra-eval-jobs returned exit code 1:
building '/nix/store/40b77hpmqsd89ar8nj7a44hdy4cn8jp0-racket-package.nix.drv'...
Racket virtual machine has run out of memory; aborting
/build/.attr-0: line 1:     2 Aborted                 racket2nix $flatArg --catalog /nix/store/347rskicxa7ifcsf325zdkr09hwqwi8a-catalog.rktd $package > $out
builder for '/nix/store/40b77hpmqsd89ar8nj7a44hdy4cn8jp0-racket-package.nix.drv' failed with exit code 134
error: build of '/nix/store/40b77hpmqsd89ar8nj7a44hdy4cn8jp0-racket-package.nix.drv' failed

There is no ulimit or anything. I think this is the machine itself running out of physical memory.