run_qemu.sh: add 20m timeout and print qemu log on failure

run_qemu.sh

@@ -9,6 +9,7 @@ tmpdir="$(mktemp -d)"
 cleanup() {
 	rv=$?
 	rm -f "$tmpdir/debian-$DEFAULT_DIST-overlay.qcow"
+	rm -f "$tmpdir/log"
 	[ -e "$tmpdir" ] && rmdir "$tmpdir"
 	if [ -e shared/result.txt ]; then
 		head --lines=-1 shared/result.txt
@@ -29,7 +30,8 @@ trap cleanup INT TERM EXIT
 qemu-img create -f qcow2 -b "$(realpath $cachedir)/debian-$DEFAULT_DIST.qcow" -F qcow2 "$tmpdir/debian-$DEFAULT_DIST-overlay.qcow"
 # to connect to serial use:
 #   minicom -D 'unix#/tmp/ttyS0'
-qemu-system-x86_64 \
+ret=0
+timeout 20m qemu-system-x86_64 \
 	-no-user-config \
 	-M accel=kvm:tcg -m 1G -nographic \
 	-object rng-random,filename=/dev/urandom,id=rng0 -device virtio-rng-pci,rng=rng0 \
@@ -38,4 +40,9 @@ qemu-system-x86_64 \
 	-serial unix:/tmp/ttyS1,server,nowait \
 	-net nic,model=virtio -net user \
 	-virtfs local,id=mmdebstrap,path="$(pwd)/shared",security_model=none,mount_tag=mmdebstrap \
-	-drive file="$tmpdir/debian-$DEFAULT_DIST-overlay.qcow",cache=unsafe,index=0,if=virtio
+	-drive file="$tmpdir/debian-$DEFAULT_DIST-overlay.qcow",cache=unsafe,index=0,if=virtio \
+	>"$tmpdir/log" 2>&1 || ret=$?
+if [ "$ret" -ne 0 ]; then
+	cat "$tmpdir/log"
+	exit $ret
+fi