[tex-k] Bug#83146: MF fatal error

[Julian Gilbey]

On Tue, Jan 23, 2001 at 08:56:51PM +0100, Fabrice Popineau wrote:
> * Thomas Esser <te@informatik.uni-hannover.de> writes:
> 
> Julian>  Wow!  I got a MetaFont "This can't happen (m)" error.  Here's
> Julian>  how I did it.
> Julian>  
> Julian>  mf '\mode:=ljfzzz; mag:=1+0/1200; nonstopmode; input xslhz20'
> Julian>  
> Julian>  Now ljfzzz is in the standard modes.mf:
> 
> Thomas>  Interesting. This also happens with teTeX's 'METAFONT,
> Thomas>  Version 2.7182 (Web2C 7.3.1)' and TeX Live 5d's 'METAFONT,
> Thomas>  Version 2.7182 (Web2C 7.3.2x)'.
> 
> As expected under win32 too (same version as on the TL5), but it may
> be the case that mf just can't handle this piece of code (well, at
> least this error is documented in the web code). Any mf wizard around
> there to look at the problem ?

When DEK writes "This can't happen" in an error message, and this
error message appears, it usually means that there is a compiler (or
web2c) bug which is being exercised.  It very occasionally means that
there's a bug in the WEB code.  This one is going to take some serious
debugging to determine....  Down to work on the WEB code!  (It'll have
to wait until later this week, though.)

Couple of thoughts, though.  I've tried compiling with gcc 2.95.2 with
-O0 compilation flag, and the error still occurs.  Does anyone have
access to non-web2c versions?  Do they exhibit the same problem?

Good luck!

   Julian

-- 
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         Julian Gilbey, Dept of Maths, Queen Mary, Univ. of London
       Debian GNU/Linux Developer,  see http://people.debian.org/~jdg
  Donate free food to the world's hungry: see http://www.thehungersite.com/