When I run spectre-meltdown-checker --paranoid --batch json, sometimes I get errors on stderr such as:

grep: /proc/32397/status: No such file or directory
grep: /proc/32398/status: No such file or directory

I believe this is due to this line of code, which is running grep over /proc/*/status:

This can fail because by the time grep starts to run, the result of the /proc/*/status expansion may no longer reflect the currently running processes (i.e. some processes may have exited already).

Maybe grep's stderr can simply be silenced?