"Unable to update/select parent row." Doesn't Provide Enough Information

[machineghost]

The error:

Unable to update/select parent row.

(from line 484 of https://github.com/mlipscombe/postgraphile-plugin-nested-mutations/blob/940c6ec412c7d4dcc1e69e5bb0e0be528fe538f1/src/PostgraphileNestedMutationsPlugin.js) doesn't explain what "parent" it's talking about.

It would be helpful if the error could instead say something more like:

Unable to update/select a row from table_b, the parent of table_a.

I would be happy to submit a PR for this if desired (I don't know Postgraphile or Postgraphile plug-in code at all, but this seems like it should be straightforward enough that I don't need to).