[NTG-context] Metapost through context incorrect `hex` function output

9 May 2025

      Hi,

I have found that the metapost `hex` function outputs a strange result 
when run through `context`.  I'm not quite sure what is leading to this 
output, maybe `hex` is redefined in `metafun`?

To reproduce, place the following in test.mp:

```
show hex "8d";
```

Then run `mpost`, which results in the correct value:

```
mpost -numbersystem=double test.mp
...
...
...
141

Running the following in context results in the following instead:

context test.mp
...
...
...
56

For some more details on tool versions:

ConTeXt: ConTeXt  ver: 2025.04.28 14:29 LMTX  fmt: 2025.5.7  int: 
english/english
Metafun: metafun xl 2025-5-9 11:26
Metapost: version 2.02 (TeX Live 2023) (kpathsea version 6.3.5)

For some reason I couldn't manage to load `metafun` in `mpost` directly 
to test it outside of ConTeXt, getting:

! I can't open file `metafun.mpii'.
l.6     input metafun.mpii
```

Thanks in advance,
Yann

-- 
Yann Herklotz