export DEBUGSOURCES="RowColumn.c MenuShell.c MenuUtil.c"
export DEBUG_FILE=/usr/tmp/LESSTIF_TRACE
+ emacs &
causes LessTif to print traces from the three named source files to a
-file in `/usr/tmp' (that file can get pretty large).
+file in `/usr/tmp' (that file can get pretty large). The above should
+be typed at the shell prompt before invoking Emacs, as shown by the
+last line above.
Running GDB from another terminal could also help with such problems.
You can arrange for GDB to run on one machine, with the Emacs display