tests/include-deb-file: run in all modes

coverage.txt

@@ -402,6 +402,7 @@ Test: error-if-stdout-is-tty
 Test: variant-custom-timeout
 
 Test: include-deb-file
+Modes: root unshare fakechroot
 Needs-APT-Config: true
 
 Test: unshare-include-deb

tests/include-deb-file

@@ -5,6 +5,18 @@ export LC_ALL=C.UTF-8
 
 trap "rm -rf /tmp/dummypkg.deb /tmp/dummypkg" EXIT INT TERM
 
+prefix=
+if [ "$(id -u)" -eq 0 ] && [ "{{ MODE }}" != "root" ] && [ "{{ MODE }}" != "auto" ]; then
+	if ! id "${SUDO_USER:-user}" >/dev/null 2>&1; then
+		if [ ! -e /mmdebstrap-testenv ]; then
+			echo "this test modifies the system and should only be run inside a container" >&2
+			exit 1
+		fi
+		useradd --home-dir "/home/${SUDO_USER:-user}" --create-home "${SUDO_USER:-user}"
+	fi
+	prefix="runuser -u ${SUDO_USER:-user} --"
+fi
+
 # instead of obtaining a .deb from our cache, we create a new package because
 # otherwise apt might decide to download the package with the same name and
 # version from the cache instead of using the local .deb
@@ -22,7 +34,7 @@ Description: dummypkg
 END
 dpkg-deb --build "/tmp/dummypkg" "/tmp/dummypkg.deb"
 
-{{ CMD }} --variant=apt --include="/tmp/dummypkg.deb" \
+$prefix {{ CMD }} --mode={{ MODE }} --variant=apt --include="/tmp/dummypkg.deb" \
 	--hook-dir=./hooks/file-mirror-automount \
 	--customize-hook='chroot "$1" dpkg-query -W -f="\${Status}\n" dummypkg | grep "^install ok installed$"' \
 	{{ DIST }} /dev/null {{ MIRROR }}