build error on centos 7.9

[spacexnasa]

xmlto: /usr/local/src/selinux-master/secilc/secilc.8.xml does not validate (status 3)
xmlto: Fix document syntax or use --skip-validation option
/usr/selinux-master/secilc/secilc.8.xml:3: warning: failed to load external entity "https://docbook.org/xml/4.4/docbookx.dtd"
"https://docbook.org/xml/4.4/docbookx.dtd">
^
warning: failed to load external entity "https://docbook.org/xml/4.4/docbookx.dtd"
validity error : Could not load the external subset "https://docbook.org/xml/4.4/docbookx.dtd"
Document /usr/local/src/selinux-master/secilc/secilc.8.xml does not validate
make[1]: *** [Makefile:51: secilc.8] Error 13
make[1]: Leaving directory '/usr/local/src/selinux-master/secilc'
make: *** [Makefile:40: install] Error 1

[vindicatorr]

I'm on Arch Linux, and for me it started with not having xmlto installed.
Then when I came across your post and a little searching, I installed docbook-xml, which got past there error, bringing me to an .xsl one, that prompted me to install docbook-xsl, getting me past that issue as well.

That got me to /usr/bin/ld: <pathTo>/usr/lib/libsemanage.so: undefined reference to ``sepol_ibendport_compare2@LIBSEPOL_1.0', pre-empted by /usr/bin/ld: warning: libsepol.so.2, needed by <pathTo>/usr/lib/libsemanage.so, not found (try using -rpath or -rpath-link), which was resolved with export LD_LIBRARY_PATH="${DESTDIR}/usr/lib:${DESTDIR}/lib" (probably all the more reason to $ source ./scripts/env_use_destdir).

But once done, everything built clean (outside a deprecation warning).