[distcc] impossible host-down warnings from ccache+distcc

[Alexandre Oliva]

Today I ran into a funny error, that took me a while to figure out.

I was using `ccache distcc gcc', but distcc was not running in two the
first 3 machines in my DISTCC_HOSTS list, so I was getting warnings
from distcc saying distccd on hosts `fri' and `livre' could not be
contacted.

After starting distccd on livre, and taking fri out of DISTCC_HOSTS, I
made some changes in my sources and build again.  Surprise: I still
got error messages about both fri and livre.

After checking DISTCC_HOSTS was set properly, exported, etc, checking
that distccd hadn't crashed on livre, etc, I figured it out: ccache
had saved the warning printed by distcc in earlier runs, and now it
was presenting them to be again.  Doh!

Just a war story I thought I'd share here.  I don't think this is
a bug in any of the tools, it's just an inconvenient side effect of
the way they work.

-- 
Alexandre Oliva   Enjoy Guarana', see http://www.ic.unicamp.br/~oliva/
Red Hat GCC Developer                 aoliva@{redhat.com, gcc.gnu.org}
CS PhD student at IC-Unicamp        oliva@{lsd.ic.unicamp.br, gnu.org}
Free Software Evangelist                Professional serial bug killer