race condition on ~/.gnupg/random_seed when signing

Desired behaviour: Signing should always fail or succeed in a deterministic manner, or provide a distinctive error message if a system failure (e.g

Desired behaviour: Signing should always fail or succeed in a deterministic manner, or provide a distinctive error message if a system failure (e.g. out of memory) occurred.

Observed behaviour: Once in a while, when doing many concurrent signing operations under heavy load, you can get an error looking the following.

gpg: fatal: can't read `/home/importd/.gnupg/random_seed': No such file or directory
secmem usage: 1472/1472 bytes in 4/4 blocks of pool 1472/32768
signature command exited with non-0 status (2)

command: gpg --clearsign --no-default-keyring --keyring /<email address hidden> --secret-keyring /<email address hidden> --default-key <email address hidden>

Interpretation: the .gnupg/random_seed might be updated in an unsafe manner, leaving a race window where the file does not exist.

Security implications: None. Triggering the race requires write access to .gnupg. If an attacker has it, you have a way bigger problem.