Yes, the `exec` should only execute if `artifact.json` exists. What I am asking is, that since you are already in the directory `$d`, what is the difference between `artifact.json` and `"$d/artifact.json"`, the change that you have introduced in #145, without documenting it in the git commit log (you have done a trial commit, which you reverted in a9e070ce4b23df4f039dc43b1f40f39827ca175c, but if you carefully diff the two commits, the effective change is adding the `$d` in there --- it is not clear whether this is an omission, or intention).