diff --git a/build_library/sysext_prod_builder b/build_library/sysext_prod_builder
index ba7c6ef856..53ba386425 100755
--- a/build_library/sysext_prod_builder
+++ b/build_library/sysext_prod_builder
@@ -67,14 +67,7 @@ create_prod_sysext() {
   sudo mv "${workdir}/sysext-build/${name}.raw" "${workdir}/sysext-build/${name}_pkginfo.raw" \
                               "${workdir}/sysext-build/${name}"_*.txt "${output_dir}"
 
-  sudo mkdir -p "${install_root}"/usr/share/flatcar/sysext || {
-    echo "DEBUG OUTPUT:"
-    mount
-    df -h
-    sudo dmesg
-    echo "END DEBUG OUTPUT"
-    exit 1
-  }
+  sudo mkdir -p "${install_root}"/usr/share/flatcar/sysext
   sudo install -m 0644 -D "${output_dir}/${name}.raw" "${install_root}"/usr/share/flatcar/sysext/
 
   sudo mkdir -p "${install_root}"/etc/extensions/
diff --git a/build_sysext b/build_sysext
index 95bc35c569..954f8790df 100755
--- a/build_sysext
+++ b/build_sysext
@@ -83,6 +83,10 @@ FLAGS "$@" || exit 1
 
 eval set -- "${FLAGS_ARGV}"
 
+# Only now can we die on error.  shflags functions leak non-zero error codes,
+# so will die prematurely if 'switch_to_strict_mode' is specified before now.
+switch_to_strict_mode -uo pipefail
+
 # Validate command line parameters
 
 SYSEXTNAME="${1:-}"
@@ -129,8 +133,6 @@ _get_sysext_arch() {
     fi
 }
 
-set -euo pipefail
-
 cleanup() {
   local dirs=(
     "${BUILD_DIR}/fs-root"
diff --git a/common.sh b/common.sh
index 0ca5346878..3dbb8040dc 100644
--- a/common.sh
+++ b/common.sh
@@ -164,9 +164,40 @@ die_notrace() {
   for line in "$@"; do
     error "${DIE_PREFIX}${line}"
   done
+  if [[ ! -e "${SCRIPTS_DIR}/NO_DEBUG_OUTPUT_DELETE_ME" ]]; then
+      error "${DIE_PREFIX}!!!!!!!!!!!!!!!!!!!!!!!!!"
+      error "${DIE_PREFIX}!! BEGIN DEBUG OUTPUT: !!"
+      error "${DIE_PREFIX}!!!!!!!!!!!!!!!!!!!!!!!!!"
+      error
+      error "${DIE_PREFIX}== MOUNT =="
+      error "${DIE_PREFIX}==========="
+      error_command_output "${DIE_PREFIX}" mount
+      error
+      error "${DIE_PREFIX}== DF =="
+      error "${DIE_PREFIX}========"
+      error_command_output "${DIE_PREFIX}" df -h
+      error
+      error "${DIE_PREFIX}== DMESG =="
+      error "${DIE_PREFIX}==========="
+      error_command_output "${DIE_PREFIX}" sudo dmesg
+      error
+      error "${DIE_PREFIX}!!!!!!!!!!!!!!!!!!!!!!!"
+      error "${DIE_PREFIX}!! END DEBUG OUTPUT: !!"
+      error "${DIE_PREFIX}!!!!!!!!!!!!!!!!!!!!!!!"
+      touch "${SCRIPTS_DIR}/NO_DEBUG_OUTPUT_DELETE_ME"
+  fi
   exit 1
 }
 
+error_command_output() {
+    local prefix=${1}; shift
+    # rest are a command to execute
+    local REPLY
+    while read -r; do
+        error "${prefix}${REPLY}"
+    done < <("${@}" 2>&1)
+}
+
 # Simple version comparison routine
 # Note: not a true semver comparison and build revisions are ignored
 cmp_ver() {
@@ -296,6 +327,8 @@ BUILD_LIBRARY_DIR="${SCRIPTS_DIR}/build_library"
 REPO_CACHE_DIR="${REPO_ROOT}/.cache"
 REPO_MANIFESTS_DIR="${REPO_ROOT}/.repo/manifests"
 
+rm -f "${SCRIPTS_DIR}/NO_DEBUG_OUTPUT_DELETE_ME" || :
+
 # Source FLATCAR_VERSION_ID from manifest.
 if [[ -f "${REPO_MANIFESTS_DIR}/version.txt" ]]; then
   # The build id may be provided externally by the build system.