R Under development (unstable) (2025-04-29 r88182 ucrt) -- "Unsuffered Consequences"
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Platform: x86_64-w64-mingw32/x64

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> library(winch)
> 
> foo <- function() {
+   purrr::map(1, ~ bar())
+ }
> 
> bar <- function() {
+   winch_call(baz)
+ }
> 
> baz <- function() {
+   winch_add_trace_back()
+ }
> 
> if (winch_available() && requireNamespace("purrr")) {
+   tryCatch(foo(), error = identity)
+ }
Loading required namespace: purrr
[[1]]
     ▆
  1. ├─base::tryCatch(foo(), error = identity)
  2. │ └─base (local) tryCatchList(expr, classes, parentenv, handlers)
  3. │   └─base (local) tryCatchOne(expr, names, parentenv, handlers[[1L]])
  4. │     └─base (local) doTryCatch(return(expr), name, parentenv, handler)
  5. └─global foo()
  6.   └─purrr::map(1, ~bar())
  7.     └─purrr:::map_("list", .x, .f, ..., .progress = .progress)
  8.       ├─purrr:::with_indexed_errors(...)
  9.       │ └─base::withCallingHandlers(...)
 10.       └─purrr:::call_with_cleanup(...)
 11.         └─`/purrr.dll`::register_frame_ctor()
 12.           └─`/purrr.dll`::register_frame_ctor()
 13.             └─.f(.x[[i]], ...)
 14.               └─global bar()
 15.                 └─winch::winch_call(baz)
 16.                   └─`/purrr.dll`::register_frame_ctor()
 17.                     └─`/purrr.dll`::register_frame_ctor()
 18.                       └─`/purrr.dll`::register_frame_ctor()
 19.                         └─`/winch.dll`::register_frame_ctor()
 20.                           └─global `<fn>`()

Warning message:
`winch_add_trace_back()` was deprecated in winch 0.1.0. 
> 
> proc.time()
   user  system elapsed 
   0.46    0.10    0.56