Interactive error messages for the Julia REPL.
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Updated Last
11 Months Ago
Started In
April 2021


Interactive error messages for the Julia REPL.



Requires Julia 1.6+.

julia> using Pkg

julia> Pkg.add("InteractiveErrors")

Add using InteractiveErrors to your startup.jl file after using Revise. If you don't have that installed yet you should install it.


Just start using your REPL normally. Once you hit an error you'll be presented with an interactive tree representing your stacktrace which you can explore. To turn interactive errors off and return to using normal stacktraces call toggle(). Call toggle() again to turn it back on.

Press up and down arrows to move through the stacktrace. Press space to fold or unfold the currently selected line. A + will appear on folded lines. Press enter once finished. If you are on a line that references a particular file then that will present additional options in the next menu. q can be pressed to exit back to the REPL.

Note: a lot of information is hidden inside some of the folded lines and some is completely stripped from the display (such as method arguments). The default choice of information to display is up for discussion. Unfolding a line containing a file and line number will display the immediate lines surrounding it.

The second menu offers several actions that can be taken on the selected line.

[press: d=done, a=all, n=none]
 • [ ] ascend
   [ ] descend
   [ ] JET
   [ ] edit
   [ ] retry
   [ ] breakpoint
   [ ] less
   [ ] clipboard
   [ ] print
   [ ] stacktrace
   [ ] exception
   [ ] backtrace

Press enter to choose the currently selected line. More than one can be chosen:

  • ascend (available if Cthulhu is loaded) calls Cthulhu.ascend on the selected method.
  • descend (available if Cthulhu is loaded) calls Cthulhu.descend on the selected method.
  • JET (available if JET is loaded) calls JET.report_call on the selected method.
  • edit opens default editor on the selected file and line.
  • retry runs the code entered in the REPL again.
  • breakpoint (available if Debugger is loaded) sets a Debugger.breakpoint on the selected file and line.
  • less opens the pager on the selected file and line.
  • clipboard copies the normal Julia stacktrace to the clipboard. Useful for posting bug reports. Don't send the interactive printout as an error message when reporting issues to packages or Julia.
  • print prints out the normal Julia stacktrace to stdout.
  • stacktrace returns the stacktrace object.
  • exception returns the exception object that was caught.
  • backtrace returns the raw backtrace object. Contains Ptrs. Not terribly useful.

More than one action can be selected at once. A common combination is edit and retry. Press d (for done) once you're finished making your choices.

Optional Packages

Additional features are available when certain packages are loaded within the REPL session.

  • Cthulhu, provides ascend and descend options on selected method.
  • Debugger, provides breakpoint on selected method.
  • JET, provides report_call on selected method.
  • JuliaFormatter, provides syntax formatting for method signatures.
  • OhMyREPL, provides syntax highlighting for source code and method signatures.

Depending on the maintenance burden of compatibility with these packages they may in future versions become direct dependencies instead of using Requires.


Most of the default coloring in the stack-tree can be adjusted to the user's liking via a simple theming system.

  • current_theme() returns the currently active theme: a nested NamedTuple of customisation options.

  • set_theme! can be used to set your own custom theme that follows the same naming scheme as the default theme. Takes either keyword arguments, or a NamedTuple.

  • reset_theme! will reset the theme.

  • adjust_theme! can be used if you only want to make some minor adjustments to the current_theme. Takes a NamedTuple or keyword arguments that will be merged with the current_theme.

The default theme is shown below:

pairs(::NamedTuple) with 19 entries:
  :function_name   => (bold = true,)
  :directory       => (color = :light_black,)
  :filename        => (color = :magenta, bold = true)
  :line_number     => (color = :green, bold = true)
  :user_stack      => (color = :green, bold = true)
  :system_stack    => (color = :red, bold = true)
  :stdlib_module   => (color = :yellow,)
  :base_module     => (color = :blue,)
  :core_module     => (color = :light_black,)
  :package_module  => (color = :cyan, bold = true)
  :unknown_module  => (color = :red,)
  :inlined_frames  => (color = :light_black,)
  :toplevel_frames => (color = :light_black,)
  :repeated_frames => (color = :red,)
  :file_contents   => (color = :light_black,)
  :signature       => (color = :light_black, format = true, highlight = true)
  :source          => (color = :normal, bold = true, highlight = true)
  :line_range      => (before = 0, after = 5)
  :charset         => :unicode

Used By Packages

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