Error handling: retrieve variables used by failed instruction

[folex]

When instructions fail, it might look like this:

 {
      "instruction": "call flattened.$.[0].peer_id (flattened.$.[0].service_id.[0] \"getPublicUser\") [] user",
      "msg": "value '[{\"peer_id\":\"12D3KooWGmJSe6Sd9ART9X5Lw6NtAZBWgcjSPHVkSgiHsNQQaMhJ\",\"relay_id\":[\"12D3KooWAPryc7ZKpbPPhEdHjLiHZYzHGYPkQGBwE77R2eRLMUtQ\"],\"service_id\":[\"8d802ce1-df37-41b3-ad94-a9984b44126d\"],\"set_by\":\"12D3KooWEWFQsdrXaUsUoX4M1V4U8gd7nHoB3j6ZSZAyaD8S3ido\",\"timestamp_created\":1638879987,\"value\":\"vc solution\",\"weight\":10000}]' is not an map-type to match field algebra with field_name = 'peer_id'",
      "peer_id": "12D3KooWEWFQsdrXaUsUoX4M1V4U8gd7nHoB3j6ZSZAyaD8S3ido",
}

Here, in the msg field we can see value of flattened.$.[0]. But we don't see the whole flattened, even though it might be very relevant for debugging the cause of error.

It would be great to be able to retrieve all the data used by failed instruction, and present it along the error. Like:

the following variables were used

flattened: [[{ peer_id: ..., relay_id: ... ]]