I was trying to build coreutils the other day and kept running into an error with docbooks.

I’d initially figured out I was missing the docbook and docbook-xsl packages (fairly obvious given it said it couldn’t find it…), but having installed them, I then got this more cryptic error: failed to load external entity "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd"

Some searching and trawling through forum posts led me to try installing docbook-xml — this solved the problem.


Try installing docbook-xml via your distro’s package manager, a la;

sudo apt install docbook-xml