Updating Category.

"Core" is just "groff, nroff, troff, libgroff".

"General" is "issues that cut broadly across the source tree".

"Makefile.am" coordinates construction of everything that gets built.  Hard to get broader than that.

Updating status based on the presumption that comment #4 supplied the Needed Info.

My reading of the problem is that the variable name in the comments is misspelled (or more specifically miscased).

The lines in question are in the section of the file headed:

# The variables that are listed in the following comments will be
# automatically set by automake in the generated Makefile.in

Some variables in these comments are all-caps and some are lowercase, presumably in line with the corresponding automake-generated variables.

From 960c22e6f75db890ce3ed5a00037c1f9712dff36 Mon Sep 17 00:00:00 2001
From: Bjarni Ingi Gislason <bjarniig@simnet.is>
Date: Thu, 23 Nov 2023 21:53:08 +0000
Subject: [PATCH]   The automake program defines a variable named 'host' with
 the canonical host specification and not a variable named 'HOST'.

Signed-off-by: Bjarni Ingi Gislason <bjarniig@simnet.is>
---
 Makefile.am | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Makefile.am b/Makefile.am
index e15a8ff0f..b61de154e 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -35,8 +35,8 @@

 # top_builddir

-# HOST
-# `HOST' is the canonical host specification,
+# host
+# `host' is the canonical host specification,
 #    CPU_TYPE-MANUFACTURER-OPERATING_SYSTEM
 # or
 #    CPU_TYPE-MANUFACTURER-KERNEL-OPERATING_SYSTEM
--
2.42.0

The patch is also in the attachment

(file #55352)

Subject: Makefile.am: variable "HOST" is not created by "automake"

  But "host" ("host_triplet = @host@" and host = @host@ in
Makefile.in) is.