More robust error throw & update Pluto (#179)

Fixes #169

Also updates Pluto to 0.19.39.

Project.toml

@@ -1,7 +1,7 @@
 name = "PlutoStaticHTML"
 uuid = "359b1769-a58e-495b-9770-312e911026ad"
 authors = ["Rik Huijzer <github@huijzer.xyz>"]
-version = "6.0.19"
+version = "6.0.20"
 
 [deps]
 AbstractTrees = "1520ce14-60c1-5f80-bbc7-55ef81b5835c"
@@ -20,7 +20,7 @@ tectonic_jll = "d7dd28d6-a5e6-559c-9131-7eb760cdacc5"
 [compat]
 AbstractTrees = "0.4"
 Gumbo = "0.8"
-Pluto = "=0.19.37"
+Pluto = "=0.19.39"
 PrecompileTools = "1.1"
 RelocatableFolders = "0.3, 1"
 julia = "1.6"

src/output.jl

@@ -174,15 +174,19 @@ function _throw_if_error(session::ServerSession, nb::Notebook)
                     continue
                 end
             end
+            filename = _indent(nb.path)
+            code = _indent(cell.code)
             body = cell.output.body::Dict{Symbol,Any}
             msg = body[:msg]::String
-            val = body[:stacktrace]::CapturedException
-            io = IOBuffer()
-            ioc = IOContext(io, :color => Base.get_have_color())
-            showerror(ioc, val)
-            error_text = _indent(String(take!(io)))
-            code = _indent(cell.code)
-            filename = _indent(nb.path)
+            error_text::String = if body[:stacktrace] isa CapturedException
+                val = body[:stacktrace]::CapturedException
+                io = IOBuffer()
+                ioc = IOContext(io, :color => Base.get_have_color())
+                showerror(ioc, val)
+                _indent(String(take!(io)))
+            else
+                _indent(string(body[:stacktrace])::String)
+            end
             msg = """
                 Execution of notebook failed.
                 Does the notebook show any errors when opening it in Pluto?