fix bugs

doc/CHANGELOG.md

@@ -14,6 +14,8 @@ Versions follow `MAJOR.MINOR.PATCH-REVISION_STAGE_N` (e.g. `3.99.1-4_rc_1`).
 - `utaz -i` / `--ignore-case` and `-s` / `--case-sensitive` switches to match
   archive extensions case-insensitively or not; the default is set by the new
   `UTAZ_DEFAULT_IGNORE_CASE` key of the `[compress]` section (default `0`).
+- `SETTRACE_DEFAULT_ENABLED` key in the new `[debug]` configuration options
+  (default `0`): activates `settrace --on` at startup of interactive shells.
 - `utaz` supports bare `.zst` files and `.tzst` archives; `taz -q` is now
   effective.
 
@@ -36,6 +38,14 @@ Versions follow `MAJOR.MINOR.PATCH-REVISION_STAGE_N` (e.g. `3.99.1-4_rc_1`).
   (it selected `xterm-direct` even inside tmux/screen or VTE terminals);
   multiplexers (tmux, screen) are now checked before emulator hints, since they
   inherit the emulator's variables.
+- `debug.sh`: the trace is now written to stderr (it used to pollute captured
+  `$(...)` output) and includes the exit status; `backtrace` and `error` are
+  exported like `settrace`; `settrace` tells its own trap from a foreign one
+  (`--status`, and `--off` no longer removes a foreign trap without `--force`);
+  `--on` when already active is only a warning; `getopt` errors name the command.
+- All modules: counters updated with `((x++))`-style commands (which return a
+  non-zero status when the value was 0) now use plain assignments, so they no
+  longer trigger the ERR trace or break `set -e`.
 - `compress.sh`: option flags and loop variables no longer leak into the
   interactive shell.
 

doc/profile.conf.example

@@ -56,7 +56,11 @@ PAGER=less
 
 # ==============================================================================
 [debug]
-# (no configurable keys yet)
+# Activate the error trace (settrace --on) at startup of interactive shells:
+# every failing command then prints its exit status and a call stack to stderr.
+# Verbose; meant for debugging scripts and the profile itself (0=no, 1=yes).
+# Can be toggled at any time with settrace --on / --off.
+#SETTRACE_DEFAULT_ENABLED=0
 
 # ==============================================================================
 [disp]

doc/profile.conf.fatalerrors

@@ -42,7 +42,12 @@ TERM=xterm-256color
 #UTAZ_DEFAULT_IGNORE_CASE=0
 
 [debug]
-# Section used by debug.sh (nothing yet)
+# Section used by debug.sh
+
+# Activate the error trace (settrace --on) at startup of interactive shells:
+# every failing command then prints its exit status and a call stack to stderr
+# (0=no, 1=yes).
+#SETTRACE_DEFAULT_ENABLED=0
 
 [disp]
 # Section used by disp.sh