diff --git a/VERSION b/VERSION
index d324349..04cc999 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.15.5
+1.15.6
diff --git a/VERSIONS.md b/VERSIONS.md
index 47658fb..9ca820d 100644
--- a/VERSIONS.md
+++ b/VERSIONS.md
@@ -17,6 +17,7 @@ Git tags: `vMAJOR.FEATURE.FIX` (e.g. `v1.8.0`). File `VERSION` omits the `v` pre
 
 | Tag | Date (UTC) | Notes |
 |-----|------------|--------|
+| **v1.15.6** | 2026-07-19 | **Bugfix:** aptdeploy ERROR jump list is self-contained — systemd httpd failures include before/after state, Result/SubState, failed units, and journal snippets (no more vague «see systemd lines»); ldd/--version errors embed concrete missing libs / exit output. |
 | **v1.15.5** | 2026-07-19 | **Bugfix:** devtesting CHF ladder — `ssh` was draining ladder stdin (only rung 1/23 ran → progress 45/98 then snap 52/52); use `ssh -n` + `mapfile`; incomplete ladder is WARN not false complete. |
 | **v1.15.4** | 2026-07-19 | **Bugfix:** French sticky titles — page label *surveillance*, stack summary *public + interne*, SUMMARY verdict/totals via i18n (`tout est clair`, `totaux :`). |
 | **v1.15.3** | 2026-07-19 | **Bugfix:** console language auto-**fr** for `*lefrancpaysan*` domains again — env `TALER_MON_LANG=en` no longer locks English; only `--lang` / `TALER_MON_LANG_SET=1` is explicit. |
diff --git a/check_apt_deploy.sh b/check_apt_deploy.sh
index 54d5704..e7bc488 100755
--- a/check_apt_deploy.sh
+++ b/check_apt_deploy.sh
@@ -127,7 +127,7 @@ _merchant_ver() {
 
 check_ldd_deep() {
   local name=$1
-  local out
+  local out missing
   out=$("$PODMAN_BIN" exec "$name" bash -lc '
     set +e
     bin=$(command -v taler-merchant-httpd)
@@ -147,15 +147,48 @@ check_ldd_deep() {
     info "ldd" "$line"
   done <<<"$out"
   if echo "$out" | grep -q 'not found'; then
-    err "ldd" "shared library missing in $name" "see ldd lines above"
+    missing=$(echo "$out" | grep 'not found' | tr '\n' ' ' | head -c 280)
+    err "ldd" "shared library missing in $name" "${missing:-not found (see ldd INFO above)}"
     return 1
   fi
   return 0
 }
 
+# Build a single-line diagnosis for err() so jump lists are self-contained
+# (operators should not need to hunt nearby INFO lines).
+_apt_systemd_diagnose() {
+  local out="$1"
+  local before after failed journal status_line result
+  before=$(echo "$out" | sed -n 's/^httpd_active: //p' | tail -1)
+  after=$(echo "$out" | sed -n 's/^after_start_httpd: //p' | tail -1)
+  failed=$(echo "$out" | sed -n 's/^failed_taler: //p' | grep -v '^none$' | tr '\n' ';' | sed 's/;$//')
+  [ -z "$failed" ] && failed=$(echo "$out" | grep -E '^\s*●\s+taler-' | head -3 | tr '\n' ';' | sed 's/;$//')
+  result=$(echo "$out" | sed -n 's/^httpd_Result: //p' | tail -1)
+  [ -z "$result" ] && result=$(echo "$out" | sed -n 's/^ *Result: //p' | head -1)
+  status_line=$(echo "$out" | sed -n 's/^httpd_status_line: //p' | tail -1)
+  journal=$(echo "$out" | sed -n 's/^httpd_journal: //p' | tr '\n' ' ' | head -c 220)
+  # fallback: first non-meta journal-ish line
+  if [ -z "$journal" ]; then
+    journal=$(echo "$out" | grep -E 'taler-merchant-httpd\[[0-9]+\]|Failed|error|Error|NRestarts|Main PID' | head -3 | tr '\n' ' ' | head -c 220)
+  fi
+  local parts=()
+  [ -n "$before" ] && parts+=("before=${before}")
+  [ -n "$after" ] && parts+=("after_start=${after}")
+  [ -n "$result" ] && parts+=("Result=${result}")
+  [ -n "$status_line" ] && parts+=("status=${status_line}")
+  [ -n "$failed" ] && [ "$failed" != "none" ] && parts+=("failed_units=${failed}")
+  [ -n "$journal" ] && parts+=("journal=${journal}")
+  if [ "${#parts[@]}" -eq 0 ]; then
+    printf '%s' "no status/journal captured (podman exec empty?)"
+    return
+  fi
+  local IFS=' · '
+  printf '%s' "${parts[*]}"
+}
+
 check_systemd() {
   local name=$1
-  local out active_httpd
+  local out active_httpd before_httpd detail
   out=$("$PODMAN_BIN" exec "$name" bash -lc '
     set +e
     echo "system: $(systemctl is-system-running 2>&1)"
@@ -163,17 +196,50 @@ check_systemd() {
     echo "target_active: $(systemctl is-active taler-merchant.target 2>&1)"
     echo "httpd_active: $(systemctl is-active taler-merchant-httpd.service 2>&1)"
     echo "httpd_enabled: $(systemctl is-enabled taler-merchant-httpd.service 2>&1)"
-    systemctl start taler-merchant.target 2>&1 | tail -5
-    sleep 2
+    # unit properties help when is-active is only "activating"/"failed"
+    echo "httpd_Result: $(systemctl show -p Result --value taler-merchant-httpd.service 2>&1)"
+    echo "httpd_SubState: $(systemctl show -p SubState --value taler-merchant-httpd.service 2>&1)"
+    echo "httpd_NRestarts: $(systemctl show -p NRestarts --value taler-merchant-httpd.service 2>&1)"
+    echo "httpd_ExecMainStatus: $(systemctl show -p ExecMainStatus --value taler-merchant-httpd.service 2>&1)"
+    echo "httpd_ExecMainCode: $(systemctl show -p ExecMainCode --value taler-merchant-httpd.service 2>&1)"
+    # one-line status (Active: failed / activating (start) …)
+    systemctl status taler-merchant-httpd.service --no-pager -l 2>&1 | head -12 | while IFS= read -r sl; do
+      echo "httpd_status: $sl"
+    done
+    # compact single-line for err detail
+    st1=$(systemctl status taler-merchant-httpd.service --no-pager -l 2>&1 | sed -n "s/^ *Active: //p" | head -1)
+    echo "httpd_status_line: ${st1:-?}"
+    systemctl start taler-merchant.target 2>&1 | tail -8 | while IFS= read -r sl; do
+      echo "start_target: $sl"
+    done
+    # wait longer: "activating" often clears only after dbinit
+    sleep 5
     echo "after_start_target: $(systemctl is-active taler-merchant.target 2>&1)"
     echo "after_start_httpd: $(systemctl is-active taler-merchant-httpd.service 2>&1)"
-    systemctl --failed --no-legend 2>/dev/null | grep -i taler || echo "failed_taler: none"
+    echo "after_httpd_Result: $(systemctl show -p Result --value taler-merchant-httpd.service 2>&1)"
+    echo "after_httpd_SubState: $(systemctl show -p SubState --value taler-merchant-httpd.service 2>&1)"
+    # journal: last failure reasons (self-contained for ERROR jump list)
+    journalctl -u taler-merchant-httpd.service -n 12 --no-pager -o cat 2>/dev/null \
+      | sed "/^$/d" | tail -8 | while IFS= read -r jl; do
+          echo "httpd_journal: $jl"
+        done
+    journalctl -u taler-merchant-dbinit.service -n 6 --no-pager -o cat 2>/dev/null \
+      | sed "/^$/d" | tail -4 | while IFS= read -r jl; do
+          echo "dbinit_journal: $jl"
+        done
+    ft=$(systemctl --failed --no-legend 2>/dev/null | grep -i taler || true)
+    if [ -n "$ft" ]; then
+      echo "$ft" | while IFS= read -r fl; do echo "failed_taler: $fl"; done
+    else
+      echo "failed_taler: none"
+    fi
   ' 2>/dev/null || echo "systemd probe failed")
   while IFS= read -r line; do
     [ -n "$line" ] || continue
     info "systemd" "$line"
   done <<<"$out"
 
+  before_httpd=$(echo "$out" | sed -n 's/^httpd_active: //p' | tail -1)
   active_httpd=$(echo "$out" | sed -n 's/^after_start_httpd: //p' | tail -1)
   # export for caller board
   APT_LAST_HTTPD="${active_httpd:-?}"
@@ -181,7 +247,17 @@ check_systemd() {
     ok "systemd httpd" "taler-merchant-httpd active after start taler-merchant.target"
     return 0
   fi
-  err "systemd httpd" "taler-merchant-httpd not active" "after_start_httpd=${active_httpd:-?} · see systemd lines"
+  detail=$(_apt_systemd_diagnose "$out")
+  # Prefer after_* Result if present
+  local after_result after_sub
+  after_result=$(echo "$out" | sed -n 's/^after_httpd_Result: //p' | tail -1)
+  after_sub=$(echo "$out" | sed -n 's/^after_httpd_SubState: //p' | tail -1)
+  [ -n "$after_result" ] && [ "$after_result" != "success" ] && detail="${detail} · after_Result=${after_result}"
+  [ -n "$after_sub" ] && detail="${detail} · after_SubState=${after_sub}"
+  # Human one-liner for jump list (no "see …" without content)
+  err "systemd httpd" \
+    "taler-merchant-httpd not active (container=${name})" \
+    "${detail}"
   return 1
 }
 
@@ -221,18 +297,21 @@ check_merchant_basics() {
   done <<<"$out"
 
   if echo "$out" | grep -qi 'error while loading shared libraries'; then
-    err "httpd" "shared library error on --version" "see basics/ldd"
+    local lib_err
+    lib_err=$(echo "$out" | grep -i 'error while loading shared libraries' | head -1 | tr '\n' ' ' | head -c 240)
+    err "httpd" "shared library error on --version" "${lib_err:-see basics INFO lines}"
     return 1
   fi
 
   set +e
-  "$PODMAN_BIN" exec "$name" taler-merchant-httpd --version >/dev/null 2>&1
-  local ec=$?
+  local ver_out ec
+  ver_out=$("$PODMAN_BIN" exec "$name" taler-merchant-httpd --version 2>&1)
+  ec=$?
   set -e
   if [ "$ec" -eq 0 ]; then
     ok "httpd --version" "exit 0"
   else
-    err "httpd --version" "exit $ec"
+    err "httpd --version" "exit $ec" "$(printf '%s' "$ver_out" | tr '\n' ' ' | head -c 240)"
     return 1
   fi
 
@@ -308,9 +387,10 @@ check_one() {
   if ! check_systemd "$name"; then
     c_fail=1
     httpd="${APT_LAST_HTTPD:-FAIL}"
+    note="${note:+$note; }httpd=${httpd}"
     # deeper ldd if httpd failed
     if [ "$ldd" != "FAIL" ]; then
-      check_ldd_deep "$name" || { ldd="FAIL"; c_fail=1; }
+      check_ldd_deep "$name" || { ldd="FAIL"; c_fail=1; note="${note:+$note; }ldd"; }
     fi
   else
     httpd="active"