String interpolation fails on Markdown

[sschmidhuber]

Hello,
I'm not sure if I identified the issue correctly, so the title might be misleading...

But here my problem, I have the following cell in my qmd file:

using Markdown

foo = "Some string"
md"$foo"

Which worked with the old IJulia based renderer and execuutes as expected in the REPL. However, if I try to render a report with QNR I get the following error:

Error 1 of 1
@ C:\...\...\test.qmd:11
Error showing value of type Markdown.MD
MethodError: no method matching latex(::IOContext{IOBuffer}, ::String)

Closest candidates are:
  latex(::IO, ::Markdown.Paragraph)
   @ Markdown C:\Users\...\AppData\Local\Programs\Julia-1.10.0\share\julia\stdlib\v1.10\Markdown\src\render\latex.jl:48 
  latex(::IO, ::Markdown.Admonition)
   @ Markdown C:\Users\...\AppData\Local\Programs\Julia-1.10.0\share\julia\stdlib\v1.10\Markdown\src\render\latex.jl:69 
  latex(::IO, ::Markdown.HorizontalRule)
   @ Markdown C:\Users\...\AppData\Local\Programs\Julia-1.10.0\share\julia\stdlib\v1.10\Markdown\src\render\latex.jl:103
  ...

Stacktrace:
 [1] latex(io::IOContext{IOBuffer}, content::Vector{Any})
   @ Markdown C:\Users\...\AppData\Local\Programs\Julia-1.10.0\share\julia\stdlib\v1.10\Markdown\src\render\latex.jl:23
 [2] latex
   @ Markdown C:\Users\...\AppData\Local\Programs\Julia-1.10.0\share\julia\stdlib\v1.10\Markdown\src\render\latex.jl:19 [inlined]
 [3] show(io::IOContext{IOBuffer}, ::MIME{Symbol("text/latex")}, md::Markdown.MD)
   @ Markdown C:\Users\...\AppData\Local\Programs\Julia-1.10.0\share\julia\stdlib\v1.10\Markdown\src\render\latex.jl:174
 [4] show(io::IOContext{IOBuffer}, m::String, x::Markdown.MD)
   @ Base.Multimedia .\multimedia.jl:123

ERROR: Internal julia server error

Adding a leading blank like md" $foo", renders correctly.

I'm using Julia 1.10 and Quarto 1.5.40.

[MichaelHatherly]

Markdown has some weird behaviours around interpolation that tends to cause this kind of problem.

In a normal REPL:

julia> using Markdown

julia> foo = "Some string"
"Some string"

julia> latex(md"$foo")
MethodError: no method matching latex(::IOBuffer, ::String)

Closest candidates are:
  latex(::IO, ::Markdown.HorizontalRule)
   @ Markdown ~/.local/share/mise/installs/julia/1.10.3/share/julia/stdlib/v1.10/Markdown/src/render/latex.jl:103
  latex(::IO, ::Markdown.Paragraph)
   @ Markdown ~/.local/share/mise/installs/julia/1.10.3/share/julia/stdlib/v1.10/Markdown/src/render/latex.jl:48
  latex(::IO, ::Markdown.BlockQuote)
   @ Markdown ~/.local/share/mise/installs/julia/1.10.3/share/julia/stdlib/v1.10/Markdown/src/render/latex.jl:56
  ...

     (stacktrace)
      (user)
 >     Markdown
   +    latex @stdlib/Markdown/src/render/latex.jl:23
   +    latex @stdlib/Markdown/src/render/latex.jl:19
   +   Base
   +   [inlined]
   +   Markdown
   +   [top-level]
   +  (system)

julia> latex(md" $foo")
"Some string\n\n"

So I'd describe this as an upstream issue and not QNR-specific.

[MichaelHatherly]

There is nothing we can do directly in this package besides hacks around the issue. I'm going to close this one @sschmidhuber as unactionable. The place to fix this is in Markdown itself.