Opening /dev/urandom seems to return -1

(dbx) print buffer
0x09001000a5f49380 
(dbx) print size
24 
(dbx) print raise
0 
(dbx) step
stopped in dev_urandom at line 311 in file "/raid/checkouts-raid/robb/nepal/build-py37/../../Python-3.7.3/Python/bootstrap_hash.c" ($t1)
  311       if (raise) {
(dbx) step
stopped in dev_urandom at line 378 in file "/raid/checkouts-raid/robb/nepal/build-py37/../../Python-3.7.3/Python/bootstrap_hash.c" ($t1)
  378           fd = _Py_open_noraise("/dev/urandom", O_RDONLY);
(dbx) next
stopped in dev_urandom at line 379 in file "/raid/checkouts-raid/robb/nepal/build-py37/../../Python-3.7.3/Python/bootstrap_hash.c" ($t1)
  379           if (fd < 0) {
(dbx) print fd
-1 
(dbx) step
stopped in dev_urandom at line 380 in file "/raid/checkouts-raid/robb/nepal/build-py37/../../Python-3.7.3/Python/bootstrap_hash.c" ($t1)
  380               return -1;
(dbx) step
stopped in dev_urandom at line 401 in file "/raid/checkouts-raid/robb/nepal/build-py37/../../Python-3.7.3/Python/bootstrap_hash.c" ($t1)
  401   }
(dbx) step
stopped in pyurandom at line 519 in file "/raid/checkouts-raid/robb/nepal/build-py37/../../Python-3.7.3/Python/bootstrap_hash.c" ($t1)
  519   }
(dbx) step
stopped in unnamed block in _Py_HashRandomization_Init at line 611 in file "/raid/checkouts-raid/robb/nepal/build-py37/../../Python-3.7.3/Python/bootstrap_hash.c" ($t1)
  611           if (res < 0) {
(dbx) step
stopped in unnamed block in _Py_HashRandomization_Init at line 612 in file "/raid/checkouts-raid/robb/nepal/build-py37/../../Python-3.7.3/Python/bootstrap_hash.c" ($t1)
  612               return _Py_INIT_USER_ERR("failed to get random numbers "
(dbx) continue
continue
^ unrecognized command
(dbx) cont
Fatal Python error: _Py_HashRandomization_Init: failed to get random numbers to initialize Python