postinstall: fontconfig abnormal exit

[Achim Gratz]

Ken Brown via Cygwin writes:
> Unfortunately, this doesn't yet fix the problem with
> fontconfig_dtd.sh.  The latter will now succeed if it is run after
> libxml2.sh, but not if it is run first.  I'm not aware of any way to
> force setup to run one postinstall script before another.

Multiple ways:

1. Make the libxml postinstall script sort lexically before any others
that depend on it.  Obviously this is brittle, but it might work in this
particular instance (autorebase does this).

2.  Make the libxml catalog creation a perpetual postinstall script with
prefix "0p_".  That only works if it doesn't depend on other postinstall
scripts having their work completed.

3. Implement and use the stratified postinstall concept originally
outlined at:
https://sourceware.org/legacy-ml/cygwin-apps/2014-12/msg00148.html

4. Use the package dependency order to order the postinstall script
activation.  With libzypp we should have the correct information, we'd
just need to somehow make the packagemeta iterator use it.  That still
won't work if we have dependency loops.

5. (Try to) Run any failed postinstalls again in setup and bail only if
the number of fails does not decrease from the last iteration.

At the time it was deemed too complicated and so we only use the "end"
strata for the perpetual postinstall scripts.  As said then, there would
need to be some serious discussion on how to coordinate the strata
assignments.


Regards,
Achim.
-- 
+<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk Blofeld]>+

Samples for the Waldorf Blofeld:
http://Synth.Stromeko.net/Downloads.html#BlofeldSamplesExtra