So, it turns out the problem is likely due to my hardware being old and
unreliable. Upon encountering the same error message, I simply ran 'make' again
to make it continue, and usually after a short period it was able to continue
going, until it happened again. I just continued doing this until
I've spent the last week trying to rebuild Dovecot on my Raspberry Pi 3
(aarch64; running Slackware ARM -current) and am running into the following
build error. I suspected it may be my recent update to Slackware but I've been
able to build the same source tarball on an x86 system running
slack
