On 2013–08–24 Hans Hagen wrote:

> Hard to say what is the issue but it is not a luajittex issue. We
> don't do anything special, for instance jit is turned off because
> there is no gain at all (actually with jit enabled, the run is
> slower).

I can confirm that. I did not find a real-world document which
compiled faster with jit. Using the virtual machine provides between
8% and 25% speed gain here.

> There is however one difference and that is the compiled lua code:
> lua and luajit have incompatible formats (apart from the fact that
> luatex is 5.2 and luajittex is 5.1++). Normally compilation happens
> automatically i.e. when a font is loaded by luatex, context will
> generate the relevant compiled file when luajittex is used.
> 
> One possibility is that there is some mismatch in version numbers
> that gets unnoticed.

Let me know if I can provide any additional info.

> In such case, as Aditya suggests, wiping the cache is an option.

That helped, indeed.

Marco