How do you fix a MySQL "Incorrect key file" error when you can't repair the table?

I'm trying to run a rather large query that is supposed to run nightly to populate a table. I'm getting an error saying Incorrect key file for table '/var/tmp/#sql_201e_0.MYI'; try to repair it but the storage engine I'm using (whatever the default is, I guess?) doesn't support repairing tables.

how do I fix this so I can run the query?

What is MySQL error?

Lost connection to MySQL server Network conditions should be checked if this is a frequent error. If an error message like “Lost connection to MySQL server” appears while querying the database, it is certain that the error has occurred because of network connection issues.

You must change the location of MySQL's temporary folder which is '/tmp' in most cases to a location with a bigger disk space. Change it in MySQL's config file.

Basically your server is running out of disk space where /tmp is located.