local_trace()

[hadley]

From renv:

renv_scope_trace <- function(what, tracer, envir = parent.frame()) {

  call <- sys.call()
  call[[1L]] <- base::trace
  call[["print"]] <- FALSE
  suppressMessages(eval(call, envir = parent.frame()))

  defer(suppressMessages(untrace(substitute(what))), envir = envir)
}

[hadley]

Hmmmm, this is not as useful as expected because .doTrace's implementation is sub-optimal:

f <- function() {
  "x"
}
trace(f, quote(return("y")))
#> [1] "f"
body(f)
#> {
#>     .doTrace(return("y"), "on entry")
#>     {
#>         "x"
#>     }
#> }
f()
#> Tracing f() on entry
#> [1] "x"


.doTrace <- function(expr, msg) {
  on <- tracingState(FALSE)
  if (on) {
    on.exit(tracingState(TRUE))
    expr
  }
  
  invisible()
}
f()
#> [1] "y"

^{Created on 2023-06-03 with reprex v2.0.2}

[hadley]

We can't figure out a work around, so I think this is unfortunately a deadend.