In the course of trying to upgrade serverless, I received the following error.
Error: EXDEV: cross-device link not permitted, rename '/tmp/serverless-binary-tmp' -> '/home/<username>/.serverless/bin/serverless'
Looking into other similar errors/questions on SO, they point out that this error arises when trying to move files across partitions/devices; trouble is that /tmp is not a separate partition to /.
So I first tried looking into changing the /tmp folder location for serverless.com, but was unable to find documentation/options to that effect.
Fortunately, a manual copy of the file seems to have been the only missing step
cp '/tmp/serverless-binary-tmp' '/home/<username>/.serverless/bin/serverless'