Removed ONESHELL hack and instead created two seperate scripts

Makefile

@@ -1,57 +1,9 @@
 .PHONY: all setup build
-all: build combine
+all: build
 
 setup:
-	./scripts/setup-host.sh
+	sudo ./scripts/setup-host.sh
 
-.ONESHELL:
 build: 
-	set -e
-
-	mkdir -p build
-
-	cd scripts
-
-	./setup-root-fs.sh
-	sudo ./make-sd-card.sh
-	./linux-dtbs.sh
-	sudo ./debian.sh
-
-.ONESHELL:
-combine:
-	set -e
-
-	mkdir -p mnt
-	mkdir -p mnt/boot
-	mkdir -p mnt/rootfs
-
-	echo "Mounting 0s"
-	sudo kpartx -a build/0s.img
-
-	cd mnt
-
-	sudo mount /dev/mapper/loop0p1 boot
-	sudo mount /dev/mapper/loop0p2 rootfs
-
-	sleep 1
-
-	echo "Copying bootloader"
-	sudo cp ../boot/* boot
-	echo "Copying Debian"
-	sudo cp -rp ../build/debian/* rootfs
-	echo "Copying dtbs"
-	sudo cp -r ../build/linux/* rootfs
-
-	sleep 1
-
-	sudo umount boot
-	sudo umount rootfs
-
-	sleep 1
-
-	cd ..
-
-	echo "Unmounting 0s"
-	sudo kpartx -d build/0s.img
-	sudo kpartx -d /dev/loop0
-	sudo losetup -d /dev/loop0
+	./prepare.sh
+	./combine.sh

combine.sh

@@ -0,0 +1,42 @@
+#!/bin/bash
+
+set -e
+set -x
+
+sudo -v
+while true; do sudo -n true; sleep 60; kill -0 \"$$\" || exit; done 2>/dev/null & 
+
+mkdir -p mnt
+mkdir -p mnt/boot
+mkdir -p mnt/rootfs
+
+echo "Mounting 0s"
+sudo kpartx -a build/0s.img
+
+cd mnt
+
+sudo mount /dev/mapper/loop0p1 boot
+sudo mount /dev/mapper/loop0p2 rootfs
+
+sleep 1
+
+echo "Copying bootloader"
+sudo cp ../boot/* boot
+echo "Copying Debian"
+sudo cp -rp ../build/debian/* rootfs
+echo "Copying dtbs"
+sudo cp -r ../build/linux/* rootfs
+
+sleep 1
+
+sudo umount boot
+sudo umount rootfs
+
+sleep 1
+
+cd ..
+
+echo "Unmounting 0s"
+sudo kpartx -d build/0s.img
+sudo kpartx -d /dev/loop0
+sudo losetup -d /dev/loop0

prepare.sh

@@ -0,0 +1,16 @@
+#!/bin/bash
+
+set -e
+set -x
+
+sudo -v
+while true; do sudo -n true; sleep 60; kill -0 \"$$\" || exit; done 2>/dev/null & 
+
+mkdir -p build
+
+cd scripts
+
+./setup-root-fs.sh
+sudo ./make-sd-card.sh
+./linux-dtbs.sh
+sudo ./debian.sh