In the ewarnings displayed after the build completes, the last line reads: ewarn "please delete it by hand, the file /etc/hotplug/pnp.rc superseeds it." "superseeds" is correctly spelled "supersedes".
Created attachment 50478 [details, diff] Spelling error patch. This patch fixes the misspelled word.
sys-apps/hotplug is useless with any recent udev version, and 2.4 kernels are no longer supported. Unmerge it and move on. WONTFIX.