It has some weird build dependencies like xsltproc, asciidoc & gettext to build docs & cargo (seems to be built in a mix of c++ & rust).

Others include: libcurl4-openssl-dev, pkg-config, libkrb5-dev (needed for curl-config), libstfl-dev, libjson-c, libsqlite3-dev.

Then the xmllint check run by a2x fails as it won’t download the DTD, so replace all instances of

$(A2X)

in the Makefile with

$(A2X) –no-xmllint