[isabelle-dev] Build error ("isabelle.Build not found")

[Makarius]

On Thu, 10 Jan 2013, Jasmin Christian Blanchette wrote:

> Am 10.01.2013 um 13:16 schrieb Jasmin Blanchette:
>
>> I just updated Isabelle to af8ecf09a58c (from a version that was one or two days old) and whenever I try to build HOL, I get this error:
>>
>>    isabelle build -c -b HOL
>>    Fehler: Hauptklasse isabelle.Build konnte nicht gefunden oder geladen werden
>>    0:00:00 elapsed time, 0:00:00 cpu time
>>
>> Mac OS X 10.6. I haven't changed any settings recently.
>
> I did some updates back and forth along the history and strangely enough 
> the problem disappeared once I went back to the above change 
> (af8ecf09a58c). Strange.

The root of the problem is here:

changeset:   50753:1253fd12ca8a
user:        wenzelm
date:        Sun Jan 06 12:44:45 2013 +0100
files:       Admin/components/components.sha1 Admin/components/main
description:
updated to scala-2.10.0;


The update from 2.9.2 to 2.10.0 introduces a discontinuity in the JVM 
bytecode emitted by the scala compiler, since it is a major release step 
by the EPFL guys.  This would be unthinkable for Java, but Scala is still 
very dynamic, and 2.10.x is indeed a big step forward.

My auto-build scripts take source versions into account (via old-fashioned 
time stamps), but not scala versions.  I will rethink this again next 
time, when there is a new scala release.

The "-f" build option was already introduced some time ago to address any 
such oddities in the jar build processs.  I am doing myself "isabelle 
jedit -b -f" quite a lot, e.g. when shuffling components and other 
administrative scripts.  This explains why I did not experience the 
breakdown myself.


 	Makarius