diff --git a/hardware/common/kit.sh b/hardware/common/kit.sh
index 00e814b..7c1b58c 100644
--- a/hardware/common/kit.sh
+++ b/hardware/common/kit.sh
@@ -192,6 +192,9 @@ do_preconditions() {
     local now; now="$(cat /sys/module/usbcore/parameters/usbfs_memory_mb 2>/dev/null || echo '?')"
     [[ $now == 1000 ]] && say "usbfs_memory_mb = $now" || warn "usbfs_memory_mb is $now, expected 1000"
     local lpm; lpm="$(probe_camera_lpm_path)"
+    # The rule acts when the camera is (re)plugged, and a udev trigger does not
+    # always replay it (on staeffelsberg it did not): write what it would write.
+    if [[ -n $lpm && "$(cat "$lpm")" != 0 ]]; then echo 0 > "$lpm" 2>/dev/null || true; fi
     if [[ -n $lpm ]]; then
         [[ "$(cat "$lpm")" == 0 ]] && say "camera USB3 LPM disabled ($lpm)" \
                                    || warn "camera USB3 LPM still $(cat "$lpm") at $lpm"
@@ -202,7 +205,10 @@ do_preconditions() {
     # The MCU has to be writable for flashing over ssh; check it the same way
     # rather than trusting that the rule took.
     local mcu_dev
-    mcu_dev="$(grep -l "^$KIT_MCU_VID\$" /sys/bus/usb/devices/*/idVendor 2>/dev/null | head -1)"
+    # `|| true`: an MCU with another vendor id (the LattePanda's own Leonardo,
+    # 3343) finds nothing here, and under set -e -o pipefail that ended the whole
+    # kit - and the installer with it - without a word.
+    mcu_dev="$(grep -l "^$KIT_MCU_VID\$" /sys/bus/usb/devices/*/idVendor 2>/dev/null | head -1 || true)"
     if [[ -n $mcu_dev ]]; then
         local node
         node="$(printf '/dev/bus/usb/%03d/%03d' "$(cat "$(dirname "$mcu_dev")/busnum")" \
diff --git a/scripts/bootstrap-tower b/scripts/bootstrap-tower
index 0d02247..8a7bdfe 100755
--- a/scripts/bootstrap-tower
+++ b/scripts/bootstrap-tower
@@ -80,6 +80,17 @@ fetch fwt_software software
 fetch fwt_firmware firmware
 
 # ---- the installer ---------------------------------------------------------
+# It runs from the software checkout, so a file named relative to where this was
+# started (--answers staeffelsberg.answers) is made absolute first.
+args=()
+while [[ $# -gt 0 ]]; do
+    args+=("$1")
+    if [[ $1 == --answers && $# -gt 1 ]]; then
+        shift
+        [[ $1 == /* ]] && args+=("$1") || args+=("$PWD/$1")
+    fi
+    shift
+done
 say "starting the installer"
 cd "$BASE/software"
-exec scripts/install-tower "$@"
+exec scripts/install-tower "${args[@]}"
diff --git a/scripts/install-tower b/scripts/install-tower
index 83f58aa..6138cef 100755
--- a/scripts/install-tower
+++ b/scripts/install-tower
@@ -74,6 +74,14 @@ while [[ $# -gt 0 ]]; do
     shift
 done
 
+# Everything it prints also goes to a log, so a long run can be read back and
+# passed on whole - a terminal's scrollback does not keep it. The questions are
+# asked on /dev/tty, so they are not affected.
+mkdir -p "$LOGDIR"
+RUN_LOG="$LOGDIR/install-$(date +%Y%m%d-%H%M%S).log"
+exec > >(tee -a "$RUN_LOG") 2>&1
+printf 'install-tower %s  (this output is also in %s)\n' "$*" "$RUN_LOG"
+
 say()  { printf '>> %s\n' "$*"; }
 warn() { printf '!! %s\n' "$*" >&2; }
 die()  { printf 'install-tower: %s\n' "$*" >&2; exit 1; }