[NTG-context] No error when loading a non-existent module

[Max Chernoff]

Hi Hans,

On Thu, 2022-08-25 at 08:57 +0200, Hans Hagen wrote:
> On 8/25/2022 2:19 AM, Max Chernoff via ntg-context wrote:
> But ... you can already do
> 
> \enabledirectives[logs.errors=*]
> 
> or
> 
> \enabledirectives[logs.errors=missing modules]

Didn't know about that, thanks.

However, this still continues processing the document and produces a PDF
at the end. All that that seems to do is make ConTeXt exit with a non-
zero status code, which is fairly easy to ignore if you're not paying
attention. 

Is there a way to make this produce a nice little "error" PDF as soon as
the error occurs just like using "\undefined" does?

> and if needed can add that line to a local cont-loc.mkxl file so that it 
> always kicks in.

Didn't know about that either.

But wouldn't it make sense for this to be an error by default? Nothing
good can happen if a user loads a non-existent (or misspelled) module.
Loading a non-existent file is a fatal error even in Plain TeX
\nonstopmode. I think that making this an error by default would break
very few working documents. In exchange, most users would get much more
helpful error messages.

Thanks,
-- Max