The jit engine complains
lua error       > error on line 12 in file C:/Users/rik/Desktop/junicode_bold.tex:
C:/ConTeXt/tex/texmf-context/tex/context/base/font-otp.lua:192: invalid value (nil) at index 1 in table for 'concat'
and produces an incorrect document (no bold or bold italic fonts used) for the following document, while the standard engine produces a correct document without complaint:
\starttypescript [serif] [junicode]
  \definefontsynonym [Serif]           [file:junicode]
  \definefontsynonym [SerifItalic]     [file:junicode-italic]
  \definefontsynonym [SerifBold]       [file:junicode-bold]
  \definefontsynonym [SerifBoldItalic] [file:junicode-bolditalic]
\stoptypescript
\starttypescript [junicode]
    \definetypeface [junicode] [rm] [serif] [junicode] [default]
\stoptypescript
\setupbodyfont[junicode]
\starttext
\fontalternative{\it\fontalternative}{\bf\fontalternative}{\bi\fontalternative}
\stoptext
I also note that the standard typescript for junicode is not useful. Beside mentioning goudysans (a cosmetic issue only, I think) the font file names do not reflect current file names for the font as available at http://junicode.sourceforge.net. If anybody has a typescript reflecting current ttf file naming, I would appreciate receiving a copy, either via the list or directly.

(The typescript in the above is stripped to a minimum, and not what I would use other than in such an example.)

--
Rik Kabel