[docs]: Revise discussion of debugging.

* Describe backtracing less circularly.
* Use active voice more.
* Drop this section's introductory paragraph from groff(7), which
  doesn't require it, being more of a reference.
* Wrap long input line.
* Bump document date.

1 files changed, 9 insertions, 17 deletions

diff --git a/man/groff.7.man b/man/groff.7.man
index af1ebbbb2..9d9ed70b2 100644
--- a/man/groff.7.man
+++ b/man/groff.7.man
@@ -7213,15 +7213,6 @@ set and test the enablement of this mode.
 .\" ====================================================================
 .
 .\" BEGIN Keep (roughly) parallel with groff.texi node "Debugging".
-.I groff
-is not the easiest language to debug,
-in part thanks to its design features of recursive interpolation and the
-use of multi-stage pipeline processing in the surrounding system.
-.
-Nevertheless there exist several features useful for troubleshooting.
-.
-.
-.P
 Preprocessors use the
 .B .lf
 request to preserve the identities of line numbers and names of input
@@ -7240,13 +7231,14 @@ and
 options of
 .MR @g@troff @MAN1EXT@ ).
 .
-Backtraces can be automatically produced when errors or warnings occur
-(the
+A trace of the formatter's input processing stack can be emitted when
+errors or warnings occur by means of
+.MR @g@troff @MAN1EXT@ 's
 .B \-b
-option of
-.MR @g@troff @MAN1EXT@ )
-or generated on demand
-.RB ( .backtrace ).
+option,
+or produced on demand with the
+.request .backtrace
+request.
 .
 .BR .tm ,
 .BR .tmc ,
@@ -7262,8 +7254,8 @@ cause early termination with successful and error exit codes
 respectively,
 to halt further processing when continuing would be fruitless.
 .
-The state of the formatter can be examined with requests that write
-lists of defined names\[em]macros,
+Examine the state of the formatter with requests that write lists of
+defined names\[em]macros,
 strings,
 and
 .RB diversions\[em]( .pm );