Backtrace truncated

[gaborcsardi]

There is a limit for the length of the error message, the default is 1000 characters, and it can be set higher, but the max is 8192. Since the trace is printed as part of the error message, this means that the trace can be truncated, which is especially not great in non-interactive sessions. E.g.

cat(deparse(substitute({
  ff <- lapply(1:10, function(i) {
    assign(
      paste0("f", i), function() do.call(paste0("f", i-1), list()),
      envir = .GlobalEnv)
  })
  
  f0 <- function() rlang::abort("oops")
  
  f10()
})), file = tmp <- tempfile(), sep = "\n")

out <- processx::run("R", c("-q", "-f", tmp))
cat(out$stderr)
#> Error: oops
#> Backtrace:
#>      █
#>   1. └─f10()
#>   2.   ├─base::do.call(paste0("f", i - 1), list())
#>   3.   └─f9()
#>   4.     ├─base::do.call(paste0("f", i - 1), list())
#>   5.     └─f8()
#>   6.       ├─base::do.call(paste0("f", i - 1), list())
#>   7.       └─f7()
#>   8.         ├─base::do.call(paste0("f", i - 1), list())
#>   9.         └─f6()
#>  10.           ├─base::do.call(paste0("f", i - 1), list())
#>  11.           └─f5()
#>  12.             ├─base::do.call(paste0("f", i - 1), list())
#>  13.             └─f4()
#>  14.               ├─base::do.call(paste0("f", i - 1), list())
#>  15.               └─f3()
#>  16.                 ├─base::do.call(paste0("f", i - 1), list())
#>  17.                 └─f2()
#>  18.                   ├─base::do.call(paste0("f", i - 1), list())
#>  19.                   └─f1()
#>  20.                     ├─base::do.call(paste0("f", i - 1), list())
#>  21.                     └─global::f0()

^{Created on 2019-10-25 by the reprex package (v0.3.0)}