Name collision causes an exception during debugging

[darkleaf]

I use di in my project and there is a lot of code like this

(ns debugger-example)

(defn service [-deps a b]
  [a b])

;; C-u C-M-x
(defn caller [{service  `service
               service* `service}]
  [(service* 1 2)
   (service  1 2)]) ;; => works without debugger [[1 2] [1 2]]

(comment
  (caller {`service (partial service :unused-deps)})
  ,,,)

Unfortunately, I can't use the debugger.

Expected behavior

I can successfully execute caller with debugger mode.

Actual behavior

It shows value of (service* 1 2) but fails on (service 1 2).

1. Unhandled clojure.lang.ArityException
   Wrong number of args (2) passed to: debugger-example/service

                  AFn.java:  429  clojure.lang.AFn/throwArity
                  AFn.java:   36  clojure.lang.AFn/invoke
                  AFn.java:  156  clojure.lang.AFn/applyToHelper
                  AFn.java:  144  clojure.lang.AFn/applyTo
                  Var.java:  707  clojure.lang.Var/applyTo
                  core.clj:  667  clojure.core/apply
                  core.clj:  662  clojure.core/apply
                 debug.clj:  542  cider.nrepl.middleware.debug/apply-instrumented-maybe
                 debug.clj:  538  cider.nrepl.middleware.debug/apply-instrumented-maybe
                      REPL:    7  debugger-example/eval23279/caller
                      REPL:   12  debugger-example/eval23283
                      REPL:   12  debugger-example/eval23283
             Compiler.java: 7177  clojure.lang.Compiler/eval
             Compiler.java: 7132  clojure.lang.Compiler/eval
                  core.clj: 3229  clojure.core/eval
                  core.clj: 3225  clojure.core/eval
    interruptible_eval.clj:   87  nrepl.middleware.interruptible-eval/evaluate/fn/fn
                  AFn.java:  152  clojure.lang.AFn/applyToHelper
                  AFn.java:  144  clojure.lang.AFn/applyTo
                  core.clj:  667  clojure.core/apply
                  core.clj: 1990  clojure.core/with-bindings*
                  core.clj: 1990  clojure.core/with-bindings*
               RestFn.java:  428  clojure.lang.RestFn/invoke
    interruptible_eval.clj:   87  nrepl.middleware.interruptible-eval/evaluate/fn
                  main.clj:  437  clojure.main/repl/read-eval-print/fn
                  main.clj:  437  clojure.main/repl/read-eval-print
                  main.clj:  459  clojure.main/repl/fn
                  main.clj:  459  clojure.main/repl
                  main.clj:  368  clojure.main/repl
               RestFn.java: 1526  clojure.lang.RestFn/invoke
    interruptible_eval.clj:   84  nrepl.middleware.interruptible-eval/evaluate
    interruptible_eval.clj:   56  nrepl.middleware.interruptible-eval/evaluate
    interruptible_eval.clj:  152  nrepl.middleware.interruptible-eval/interruptible-eval/fn/fn
                  AFn.java:   22  clojure.lang.AFn/run
               session.clj:  218  nrepl.middleware.session/session-exec/main-loop/fn
               session.clj:  217  nrepl.middleware.session/session-exec/main-loop
                  AFn.java:   22  clojure.lang.AFn/run
               Thread.java: 1583  java.lang.Thread/run

Environment & Version information

cider-nrepl version

• cider-nrepl 0.45.0
• CIDER 1.13.1 (Santiago)
• nREPL 1.0.0

Java version

21.0.1

Operating system

mac os x 13.6.1

[vemv]

Interesting, thanks!

Worth noting, service (the local variable) shadows service (the var).

Linters such as clj-kondo https://github.com/clj-kondo/clj-kondo/blob/b5c63bfc9ee0066b202945a6186749af8e66af6e/doc/linters.md#shadowed-var and Eastwood https://github.com/jonase/eastwood?tab=readme-ov-file#local-shadows-var can lint against that kind of thing, as it's commonly frowned upon practice.

I'm not saying "don't do that", but generally, misc tooling will work better when following the best practice.

Most practically, here it means that you might not get support quickly (the debugger middleware doesn't often get maintenance).

[vemv]

Sure, thanks! We can figure out how to add a test as you open the PR.