run-tests cd into each test directory before running it

tests/smoke/run.sh

@@ -1,14 +1,14 @@
 set -e
-NIXPKGS_ALLOW_UNSUPPORTED_SYSTEM=1 nix-build  -I liminix-config=./tests/smoke/configuration.nix --arg device "import ./devices/$DEVICE.nix" -o smoke.img
+NIXPKGS_ALLOW_UNSUPPORTED_SYSTEM=1 nix-build '<liminix>' -I liminix-config=./configuration.nix --arg device "import <liminix/devices/$DEVICE.nix>" -A outputs.squashfs -o smoke.img $*
 
 TESTS=$(cat <<"EOF"
 
 trap 'echo "command $(eval echo $BASH_COMMAND) failed with exit code $?"; exit $?' ERR
 dest_path=${TMPDIR}/smoke.img-$$
 echo $dest_path
-unsquashfs -q -d $dest_path smoke.img
+unsquashfs -q -d $dest_path -excludes smoke.img  /dev
 cd $dest_path;
-db=*-s6-rc-db/compiled/
+db=nix/store/*-s6-rc-db/compiled/
 test -d $db
 chmod -R +w $db
 # check we have closure of config.services (lo.link.service exists only