[metapost] results-caching bugs

[Nicola]

In article <201110272336.p9RNapPX031960 at tahoe.cs.dartmouth.edu>,
 Doug McIlroy <doug at cs.dartmouth.edu> wrote:

> The transcript below demonstrates the bugs.  File fig.mp is good
> Tex but bad Troff (Eqn).  Mpost is run four times on that file:
> 
> 1. Mpost expects Tex, finds it and successfully outputs fig.1.
> 2. Mpost expects Troff, finds fig.mpx and accepts relict fig.1.
> 3. Mpost expects Troff, finds no fig.mpx, detects bad input and 
>    leaves incomplete fig.1.
> 4. Mpost expects Tex, finds fig.mpx and accepts garbage fig.1.

I am not sure that this can be considered as a bug, because the edge-case 
workflow you are describing (compile with mp, then compile the same file with mp 
-T) is not supported by mp. The problem of left-overs, as Taco has noted 
already, is common to all TeX-related tools, and one has to live with it. I'd 
suggest using a TeX-aware editor that has an option to clean auxiliary files 
before typesetting.

Nicola