Replying to hlee@…:
It appears I am attempting to retrieve the port from macports.org.
The output you provided does not show what mirror you retrieved the files from. Please sudo port clean --all libpaper
to clean out your prior attempt, sudo port selfupdate
to ensure you have the latest MacPorts base and port definitions, then try again, and if it fails with a checksum error again, immediately copy the output (which should, just the first time after you try after cleaning --all, show you which mirror you're downloading from) and paste it here.