common: Print debugging info along the backtrace

Recently we had some problems with read-only filesystems, that pop up
in different places. It may be easier to catch if the debugging info
is printed in an error case instead of just one specific location.

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/

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.