[Dev-luatex] Rationale for using putenv?

[Taco Hoekwater]

> 
> Anyway, option a) presumably also would require to place the table
> keeping score of environment variables into Lua context 0, in order to
> make sure that it remains available until LuaTeX exits.

There is an os.env table already, but it is initialized only once.
In any case, I will probably move to the 'ex' interface soon instead
of my own code+LuaFileSystem:

   http://lua-users.org/wiki/ExtensionProposal

Best wishes, Taco