Add failure checks

build.sh

@@ -311,24 +311,33 @@ case "$IMAGE_TYPE" in
 		debug "Stage 1/2 - File(s)"
 		# Setup custom debian-cd to make our changes
 		cp -aT /usr/share/debian-cd simple-cdd/debian-cd
+		[ $? -eq 0 ] || failure
+
 		# Keep 686-pae udebs as we changed the default from 686
 		# to 686-pae in the debian-installer images
 		sed -i -e '/686-pae/d' \
 			simple-cdd/debian-cd/data/$CODENAME/exclude-udebs-i386
+		[ $? -eq 0 ] || failure
 
 		# Update the post-install script
 		cp bin/kali-finish-install simple-cdd/profiles/kali.postinst
+		[ $? -eq 0 ] || failure
 
 		# Configure the kali profile with the packages we want
 		grep -v '^#' kali-config/installer-$KALI_VARIANT/packages \
 			> simple-cdd/profiles/kali.downloads
+		[ $? -eq 0 ] || failure
+
 		# Tasksel is required in the mirror for debian-cd
 		echo tasksel >> simple-cdd/profiles/kali.downloads
+		[ $? -eq 0 ] || failure
+
 		# Grub is the only supported bootloader on arm64
 		# so ensure it's on the iso for arm64.
 		if [ "$KALI_ARCH" = "arm64" ]; then
 			debug "arm64 GRUB"
 			echo "grub-efi-arm64" >> simple-cdd/profiles/kali.downloads
+			[ $? -eq 0 ] || failure
 		fi
 
 		# Run simple-cdd