Nicola <nvitacolonna@gmail.com> wrote on Wed., 13. Apr. 2016 19:36:

I have found an old document of mine, which uses a
(slightly customized) pret-c.lua, located inside the project's folder.
It compiles, but I don't get syntax highlighting. Is it because pret-c
is not searched in the project's directory? 

Alternatively you can set the TEXMF_LOCAL environment variable to some directory where your "private" texmf-tree resides. Note that after this you have to run
    context --generate
in order for context to find the modules in your texmf-tree.
Also note that the compilation logfile written by context tells you what modules have been found in which locations.

I hope this helps,

Christoph