Exception data is not pretty printed anymore

[rrudakov]

Expected behavior

Exception data is pretty printed in *cider-error* buffer. Example from CIDER 1.17.1:

Actual behavior

Exception data is printed in one line and truncated. Example from CIDER 1 .18-SNAPSHOT:

the data is truncated and there is no way to see the full map:

Steps to reproduce the problem

Evaluate a for that throws an exception with a big ex-data map. For example:

(throw (ex-info "The error with a very big data"
                  {:user-id 12345
                   :username "john.doe"
                   :email "[email protected]"
                   :profile {:first-name "John"
                             :last-name "Doe"
                             :age 30
                             :address {:street "123 Main St"
                                       :city "Anytown"
                                       :zip "12345"}
                             :interests ["programming" "hiking" "reading"]}
                   :orders [{:order-id 1001 :items ["book" "pen"] :total 25.00}
                            {:order-id 1002 :items ["laptop"] :total 1200.00}]
                   :active? true
                   :created-at #inst "2023-10-27T10:00:00.000-00:00"
                   :settings {:theme "dark", :notifications true}}))

Environment & Version information

CIDER version information

;; CIDER 1.18.0-snapshot (package: 20250407.822), nREPL 1.3.1
;; Clojure 1.12.0, Java 23.0.2

Lein / Clojure CLI version

Clojure CLI 1.12

Emacs version

GNU Emacs 31.0.50 (build 1, aarch64-apple-darwin24.3.0, NS appkit-2575.40 Version 15.3.2 (Build 24D81)) of 2025-04-03

Operating system

MacOS

[bbatsov]

@alexander-yakushev Would you mind taking a look?

[alexander-yakushev]

Hi, this is intentional as of #3790. Instead of pretty-printing the stacktrace, it is expected that the user clicks the exception to open it (together with its data) in the inspector. We're still lacking a good way to hint the user this is possible – that's what needs to be fixed indeed.

[rrudakov]

@alexander-yakushev how should I click to open the inspector? I tried with mouse and I tried using RET key, but nothing happens. In the echo area I see the message Buffer is read-only: #<buffer *cider-error*>

[alexander-yakushev]

It works by clicking on the exception class.

Very obscure, I know.

[rrudakov]

Indeed, it works, thanks! For the record, it's bound to i key if one wants to use keyboard :)

Not sure if I should close this issue.

[bbatsov]

Probably we should insert some button after it or under it.

[bbatsov]

Not sure if I should close this issue.

Let's keep it open for now, as admittedly the UI is confusing right now and we'll need to improve it a bit, before cutting the next CIDER release.

[alexander-yakushev]

Can be closed now as addressed by #3807.

[rrudakov]

Thank you @alexander-yakushev!