At 2025-09-30T18:17:26+0000, Bjarni Ingi Gislason wrote:

quoted

  This is shown with (my version of test-groff)

It's not just your version of "test-groff", a shell script built but not
installed by the groff build process, but your version/fork of groff as
a project.

In particular,

quoted

test-groff -man -t -ww -b -z man7/vdso.7

troff: backtrace: file 'man7/vdso.7':146
troff:man7/vdso.7:146: warning: trailing space in the line

...the foregoing is not a diagnostic message that GNU groff emits.

It's an unhelpful message in at least two respects.

* It doesn't identify a problem.  This sort of noun phrase is not a
  useful diagnostic.
* Because input lines and output lines are distinguishable in any
  program that fills, joins, breaks, or "folds" text, this diagnostic is
  furthermore unclear.

Moreover, trailing spaces on input lines are not _invalid_ in any *roff,
excepting possibly yours, which is private to you.

[...]

quoted

  Visible change is two empty lines after a table instead of a single
  line.

If that's the problem, then that is the defect you should report, not a
wall of (arguably spurious) warning diagnostics.

quoted

  A full stop should be used in front of '\}' to make the line a
  control line.

This counsel has nothing to do with the diagnostic you quoted
(repeatedly).

Here's the source:

$ sed -n '143,147p' man7/vdso.7
The exact name should not matter to any code, so do not hardcode it.
.if t \{\
.ft CW
\}
.TS

There are other valid (and economical) ways to employ the `\}` escape
sequence.  I've pointed this out to you before, recently.

https://lists.gnu.org/archive/html/bug-groff/2025-08/msg00177.html

So this is one possible fix:

 The exact name should not matter to any code, so do not hardcode it.
 .if t \{\
 .ft CW
-\}
+.\}
 .TS

...but so is this:

 The exact name should not matter to any code, so do not hardcode it.
 .if t \{\
-.ft CW
+.ft CW\}
 .TS

...and this:

 The exact name should not matter to any code, so do not hardcode it.
-.if t \{\
+.if t ft CW
-\}
 .TS

...and this:

diff --git a/man/man7/vdso.7 b/man/man7/vdso.7
index 0dc8bf6f2..88a561222 100644
--- a/man/man7/vdso.7
+++ b/man/man7/vdso.7

@@ -141,11 +141,9 @@ .SS vDSO names
 .BR ldd (1)
 output.
 The exact name should not matter to any code, so do not hardcode it.
-.if t \{\
-.ft CW
-\}
+.EX
 .TS
-l l.
+L L.
 user ABI       vDSO name
 _
 aarch64        linux\-vdso.so.1

@@ -162,10 +160,7 @@ .SS vDSO names
 x86-64 linux\-vdso.so.1
 x86/x32        linux\-vdso.so.1
 .TE
-.if t \{\
-.in
-.ft P
-\}
+.EE
 .SS strace(1), seccomp(2), and the vDSO
 When tracing system calls with
 .BR strace (1),

...but my recommendation is be the following.

diff --git a/man/man7/vdso.7 b/man/man7/vdso.7
index 0dc8bf6f2..750119996 100644
--- a/man/man7/vdso.7
+++ b/man/man7/vdso.7

@@ -141,11 +141,10 @@ .SS vDSO names
 .BR ldd (1)
 output.
 The exact name should not matter to any code, so do not hardcode it.
-.if t \{\
-.ft CW
-\}
+.P
 .TS
-l l.
+Lb Lb
+L  L .
 user ABI       vDSO name
 _
 aarch64        linux\-vdso.so.1

@@ -162,10 +161,6 @@ .SS vDSO names
 x86-64 linux\-vdso.so.1
 x86/x32        linux\-vdso.so.1
 .TE
-.if t \{\
-.in
-.ft P
-\}
 .SS strace(1), seccomp(2), and the vDSO
 When tracing system calls with
 .BR strace (1),

...and so on similarly for the rest of the tables in the document.

I can't imagine why anyone wanted them all in a constant-width face.

quoted

  This also the case in some other files.

That claim doesn't help anyone.  If trailing spaces in "the line" don't
cause rendering problems in "other files", then there is no urgency to
change them, and, arguably, not even a defect in the first place.

Regards,
Branden