help? mode: Error showing value of type Markdown.MD

[mbauman]

On today's nightly:

help?> round
search: round rounding count rand run RoundUp count!

  round(z::Complex[, RoundingModeReal, [RoundingModeImaginary]])
  round(z::Complex[, RoundingModeReal, [RoundingModeImaginary]]; digits=0, base=10)
  round(z::Complex[, RoundingModeReal, [RoundingModeImaginary]]; sigdigits, base=10)

  Return the nearest integral value of the same type as the complex-valued z
  to z, breaking ties using the specified RoundingModes. The first
  RoundingMode is used for rounding the real components while the second is
  used for rounding the imaginary components.

  RoundingModeReal and RoundingModeImaginary default to RoundNearest, which
  rounds to the nearest integer, with ties (fractional values of 0.5) being
  rounded to the nearest even integer.

  Examples
  ≡≡≡≡≡≡≡≡

  julia> round(3.14 + 4.5im)
  3.0 + 4.0im

  julia> round(3.14 + 4.5im, RoundUp, RoundNearestTiesUp)
  4.0 + 5.0im

  julia> round(3.14159 + 4.512im; digits = 1)
  3.1 + 4.5im

  julia> round(3.14159 + 4.512im; sigdigits = 3)
  3.14 + 4.51im

  ────────────────────────────────────────────────────────────────────────────

Error showing value of type Markdown.MD:
ERROR: MethodError: no method matching keys(::Nothing)
The function `keys` exists, but no method is defined for this combination of argument types.

Closest candidates are:
  keys(::Cmd)
   @ Base process.jl:716
  keys(::Core.SimpleVector)
   @ Base essentials.jl:945
  keys(::Base.TermInfo)
   @ Base terminfo.jl:232
  ...

Stacktrace:
  [1] pairs(collection::Nothing)
    @ Base ./abstractdict.jl:178
  [2] findfirst(testf::JuliaSyntaxHighlighting.var"#17#18", A::Nothing)
    @ Base ./array.jl:2433
  [3] _hl_annotations!(highlights::Vector{…}, lineage::JuliaSyntaxHighlighting.GreenLineage, ctx::JuliaSyntaxHighlighting.HighlightContext{…}; syntax_errors::Bool)
    @ JuliaSyntaxHighlighting ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.13/JuliaSyntaxHighlighting/src/JuliaSyntaxHighlighting.jl:222
  [4] _hl_annotations!
    @ ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.13/JuliaSyntaxHighlighting/src/JuliaSyntaxHighlighting.jl:181 [inlined]
  [5] _hl_annotations!(highlights::Vector{…}, lineage::JuliaSyntaxHighlighting.GreenLineage, ctx::JuliaSyntaxHighlighting.HighlightContext{…}; syntax_errors::Bool)
    @ JuliaSyntaxHighlighting ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.13/JuliaSyntaxHighlighting/src/JuliaSyntaxHighlighting.jl:343
  [6] _hl_annotations!
    @ ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.13/JuliaSyntaxHighlighting/src/JuliaSyntaxHighlighting.jl:181 [inlined]
  [7] _hl_annotations!(highlights::Vector{…}, lineage::JuliaSyntaxHighlighting.GreenLineage, ctx::JuliaSyntaxHighlighting.HighlightContext{…}; syntax_errors::Bool)
    @ JuliaSyntaxHighlighting ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.13/JuliaSyntaxHighlighting/src/JuliaSyntaxHighlighting.jl:343
  [8] _hl_annotations!
    @ ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.13/JuliaSyntaxHighlighting/src/JuliaSyntaxHighlighting.jl:181 [inlined]
  [9] _hl_annotations!(highlights::Vector{…}, lineage::JuliaSyntaxHighlighting.GreenLineage, ctx::JuliaSyntaxHighlighting.HighlightContext{…}; syntax_errors::Bool)
    @ JuliaSyntaxHighlighting ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.13/JuliaSyntaxHighlighting/src/JuliaSyntaxHighlighting.jl:343
 [10] _hl_annotations!
    @ ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.13/JuliaSyntaxHighlighting/src/JuliaSyntaxHighlighting.jl:181 [inlined]
 [11] #_hl_annotations#10
    @ ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.13/JuliaSyntaxHighlighting/src/JuliaSyntaxHighlighting.jl:170 [inlined]
 [12] _hl_annotations
    @ ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.13/JuliaSyntaxHighlighting/src/JuliaSyntaxHighlighting.jl:167 [inlined]
 [13] highlight
    @ ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.13/JuliaSyntaxHighlighting/src/JuliaSyntaxHighlighting.jl:392 [inlined]
 [14] highlight
    @ ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.13/JuliaSyntaxHighlighting/src/JuliaSyntaxHighlighting.jl:383 [inlined]
 [15] term(io::IOContext{REPL.LimitIO{Base.TTY}}, md::Markdown.Code, columns::Int64)
    @ Markdown ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.13/Markdown/src/render/terminal/render.jl:120
 [16] term(io::IOContext{REPL.LimitIO{Base.TTY}}, content::Vector{Any}, cols::Int64)
    @ Markdown ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.13/Markdown/src/render/terminal/render.jl:10
 [17] term(io::IOContext{REPL.LimitIO{Base.TTY}}, md::Markdown.MD, columns::Int64)
    @ Markdown ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.13/Markdown/src/render/terminal/render.jl:18
 [18] term(io::IOContext{REPL.LimitIO{Base.TTY}}, content::Vector{Any}, cols::Int64)
    @ Markdown ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.13/Markdown/src/render/terminal/render.jl:13
 [19] term(io::IOContext{REPL.LimitIO{Base.TTY}}, md::Markdown.MD, columns::Int64)
    @ Markdown ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.13/Markdown/src/render/terminal/render.jl:18
 [20] term(io::IOContext{REPL.LimitIO{Base.TTY}}, content::Vector{Any}, cols::Int64)
    @ Markdown ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.13/Markdown/src/render/terminal/render.jl:13
 [21] term
    @ ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.13/Markdown/src/render/terminal/render.jl:18 [inlined]
 [22] term
    @ ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.13/Markdown/src/render/terminal/render.jl:17 [inlined]
 [23] show(io::IOContext{REPL.LimitIO{Base.TTY}}, ::MIME{Symbol("text/plain")}, md::Markdown.MD)
    @ Markdown ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.13/Markdown/src/render/terminal/render.jl:231
 [24] show_repl(io::IO, mime::MIME{Symbol("text/plain")}, x::Any)
    @ REPL ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.13/REPL/src/REPL.jl:574
 [25] show_limited(io::IO, mime::MIME, x::Any)
    @ REPL ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.13/REPL/src/REPL.jl:543
 [26] (::REPL.var"#display##0#display##1"{REPL.REPLDisplay{…}, MIME{…}, Base.RefValue{…}})(io::Any)
    @ REPL ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.13/REPL/src/REPL.jl:566
 [27] with_repl_linfo(f::Any, repl::REPL.LineEditREPL)
    @ REPL ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.13/REPL/src/REPL.jl:867
 [28] display(d::REPL.REPLDisplay, mime::MIME{Symbol("text/plain")}, x::Any)
    @ REPL ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.13/REPL/src/REPL.jl:552
 [29] display
    @ ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.13/REPL/src/REPL.jl:572 [inlined]
 [30] display(x::Any)
    @ Base.Multimedia ./multimedia.jl:340
 [31] #invokelatest#1
    @ ./essentials.jl:1057 [inlined]
 [32] invokelatest
    @ ./essentials.jl:1053 [inlined]
 [33] print_response(errio::IO, response::Any, show_value::Bool, have_color::Bool, specialdisplay::Union{…})
    @ REPL ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.13/REPL/src/REPL.jl:0
 [34] (::REPL.var"#print_response##0#print_response##1"{REPL.LineEditREPL, Pair{Any, Bool}, Bool, Bool})(io::Any)
    @ REPL ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.13/REPL/src/REPL.jl:584
 [35] with_repl_linfo(f::Any, repl::REPL.LineEditREPL)
    @ REPL ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.13/REPL/src/REPL.jl:867
 [36] print_response(repl::REPL.AbstractREPL, response::Any, show_value::Bool, have_color::Bool)
    @ REPL ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.13/REPL/src/REPL.jl:582
 [37] (::REPL.var"#do_respond#71"{…})(s::REPL.LineEdit.MIState, buf::Any, ok::Bool)
    @ REPL ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.13/REPL/src/REPL.jl:1209
 [38] #invokelatest#1
    @ ./essentials.jl:1057 [inlined]
 [39] invokelatest
    @ ./essentials.jl:1053 [inlined]
 [40] run_interface(terminal::REPL.Terminals.TextTerminal, m::REPL.LineEdit.ModalInterface, s::REPL.LineEdit.MIState)
    @ REPL.LineEdit ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.13/REPL/src/LineEdit.jl:2852
 [41] run_frontend(repl::REPL.LineEditREPL, backend::REPL.REPLBackendRef)
    @ REPL ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.13/REPL/src/REPL.jl:1680
 [42] (::REPL.var"#59#60"{REPL.LineEditREPL, REPL.REPLBackendRef})()
    @ REPL ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.13/REPL/src/REPL.jl:686
Some type information was truncated. Use `show(err)` to see complete types.

julia> versioninfo()
Julia Version 1.13.0-DEV.52
Commit 6b39a818bdc (2025-02-13 17:11 UTC)
Build Info:
  Official https://julialang.org release
Platform Info:
  OS: macOS (arm64-apple-darwin24.0.0)
  CPU: 8 × Apple M1 Pro
  WORD_SIZE: 64
  LLVM: libLLVM-18.1.7 (ORCJIT, apple-m1)
  GC: Built with stock GC
Threads: 1 default, 1 interactive, 1 GC (on 6 virtual cores)

[tecosaur]

I suspect this will be fixed after JuliaLang/JuliaSyntaxHighlighting.jl#9 is merged and the stdlib bumped.

[tecosaur]

Said PR has been merged, now the stdlib just needs to be bumped.

[mbauman]

@tecosaur are there regression tests for this behavior either here or in JuliaSyntaxHighlighting? I didn't see it immediately, but it would be very good to have.

[tecosaur]

tecosaur are there regression tests for this behavior either here or in JuliaSyntaxHighlighting? I didn't see it immediately, but it would be very good to have.

This is something that I've thought of, but it's a little tricky. While we could write a test for this single syntax form, it's very whack-a-mole. What's really needed is defensive coding that systematically avoids making any assumptions about the structure of JuliaSyntax's output (in a recent commit I've moved further towards this), and a proper fuzz-test type approach that generates all sorts of unusual forms.

Given this was part of adapting to a change that happened in the JuliaSyntax 1.0 breaking release, I'm not sure that a regression test for the particular syntax encountered here would be of much value, but what I describe above definitely would be.

Something else that could be useful is to just try highlighting a few sample files that are quite diverse in terms of syntax.