Attached is a patch that fixes the build for the texi doc file.
Claudio
--- psgml.texi.orig 2020-10-21 16:44:04.683099515 +0300
+++ psgml.texi 2020-10-21 16:43:52.734915699 +0300
@@ -1572,7 +1572,7 @@ Default: @code{t}.
Set the variable @code{sgml-display-char-list-filename} to a file that
contains mappings between all characters present in the presentation
-character set, and their "standard replacement text" names, e.g. "å"
+character set, and their "standard replacement text" names, e.g. "@U{00e5}"
-> "[aring ]", e.t.c.
The default value for this variable is `iso88591.map'.
