* What led up to the situation?
Checking for defects with
[test-]groff -mandoc -t -K utf8 -rF0 -rHY=0 -ww -b -z < "man page"
[test-groff is a script in the repository for "groff"] (local copy and
"troff" slightly changed by me).
* What was the outcome of this action?
troff: backtrace: file '<stdin>':63
troff:<stdin>:63: warning: macro 'DS' not defined
troff: backtrace: file '<stdin>':90
troff:<stdin>:90: warning: macro 'DE' not defined
* What outcome did you expect instead?
No output (no warnings).
-.-
General remarks and further material, if a diff-file exist, are in the
attachments.