=== modified file 'common.zsh'
--- common.zsh	2017-11-15 00:46:28 +0000
+++ common.zsh	2017-11-15 00:36:27 +0000
@@ -121,10 +121,9 @@
 	fi
 	target=$(base64 -w 0 <<<${(j::)${(oq)new_vars}} | tr /+ _-).$name \
 		|| die "Failed to generate target name"
-	"$run[@]" meta/$target || die "Building $name failed ($new_vars)"
+	"$run[@]" meta/$target || die "Building $name failed ($target)"
 
 	if (($#lift)); then
-		[[ -f meta/$target ]] || die "Building $name produced no output ($new_vars)"
 		# lift %variables from calee to caller
 		local lift_vars arg
 		for arg in "${(s::Q)$(<meta/$target)}"; do