diff --git a/lib/functions/main/default-build.sh b/lib/functions/main/default-build.sh
index 0604016fbc..9a6045973c 100644
--- a/lib/functions/main/default-build.sh
+++ b/lib/functions/main/default-build.sh
@@ -188,6 +188,10 @@ function main_default_build_single() {
 		display_alert "Target directory" "${DEB_STORAGE}/" "info"
 		display_alert "File name" "${CHOSEN_KERNEL}_${REVISION}_${ARCH}.deb" "info"
 	fi
+	
+	# At this point, the WORKDIR should be clean. Add debug info.
+	debug_tmpfs_show_usage "AFTER ALL PKGS BUILT"
+	
 
 	# build rootfs, if not only kernel.
 	if [[ $KERNEL_ONLY != yes ]]; then
diff --git a/lib/functions/main/rootfs-image.sh b/lib/functions/main/rootfs-image.sh
index 83e6d863c7..ad9da96b4c 100644
--- a/lib/functions/main/rootfs-image.sh
+++ b/lib/functions/main/rootfs-image.sh
@@ -81,6 +81,16 @@ function build_rootfs_and_image() {
 	# clean up / prepare for making the image
 	umount_chroot "$SDCARD"
 
+	# obtain the size, in MiB, of "${SDCARD}" at this point.
+	declare -i rootfs_size_mib
+	rootfs_size_mib=$(du -sm "${SDCARD}" | awk '{print $1}')
+	display_alert "Actual rootfs size" "${rootfs_size_mib}MiB" ""
+
+	# warn if rootfs_size_mib is higher than the tmpfs_estimated_size
+	if [[ ${rootfs_size_mib} -gt ${tmpfs_estimated_size} ]]; then
+		display_alert "Rootfs actual size is larger than estimated tmpfs size" "${rootfs_size_mib}MiB > ${tmpfs_estimated_size}MiB" "wrn"
+	fi
+
 	# ------------------------------------ UP HERE IT's 'rootfs' stuff -------------------------------
 
 	#------------------------------------ DOWN HERE IT's 'image' stuff -------------------------------
@@ -114,6 +124,8 @@ function list_installed_packages() {
 function trap_handler_cleanup_rootfs_and_image() {
 	display_alert "Cleanup for rootfs and image" "trap_handler_cleanup_rootfs_and_image" "cleanup"
 
+	debug_tmpfs_show_usage "before cleanup of rootfs"
+
 	cd "${SRC}" || echo "Failed to cwd to ${SRC}" # Move pwd away, so unmounts work
 	# those will loop until they're unmounted.
 	umount_chroot_recursive "${SDCARD}" "SDCARD" || true