🚀 go-pugleaf

>Find a terminal whose /etc/termcap description does not have ds, es, or
>fs. Set your TERMCAP variable to be the standard termcap for that
>terminal, plus any ds, es, and fs strings. Observe that sysline does
>not recognize the environment TERMCAP.

It worked for me when I compiled the "sysline" from the 4.3BSD source
(making minor changes as necessary, none of which had anything to do
with the "termcap" code) and set TERMCAP to the standard "sun" entry
plus the stuff from the "sun-s" entry.

>Not having sysline source, I have so far been content to write my own
>code to use the terminal status line. I suspect that termcap is used in
>sysline without using the termcap(3) routines.

Nope - at least not in the 4.3BSD version; it uses the standard
"termcap" routines to fetch them.  Maybe the versions you worked with
either 1) were built against a broken version of the "termcap" library
that fails to recognize TERMCAP or 2) were older versions that didn't
use the "termcap" library?