Re: better RSYNC mirroring , for .debs and others
> > > I'm not arguing the rest of your points, but I'm curious about
> > > this one. IIRC, the last thing a full bootstrap of GCC does,
> > > after building stage one binaries with the native compiler,
> >
> > Hum, It *used* to do this, can't seem to get it to do it today though
> > <oh well>
> >
> > IIRC it only applied to debug information, it included timestamps or
> > some such.
>
> There is a small header at the beginning of an object file which is
> different each time, because it contains a time stamp.
>
> This is why 'make compare' removes the first 16 bytes of the object
> files before comparing.
>
> for file in *$(objext); do \
> tail +16c ./$$file > tmp-foo1; \
> tail +16c stage$$stage/$$file > tmp-foo2 \
> && (cmp tmp-foo1 tmp-foo2 > /dev/null 2>&1 || echo $$file differs >> .bad_compare) || true; \
> done
Yes, I've seen that stuff fly (or crawl) past while building gcc, but
I don't understand in what circumstances it's required. I can't get
gcc to include timestamps when I try it.
I think the main spurious diff culprit in debs is gzip (and tar z).
It occurred to me that perhaps debs should be built with a
hacked/wrapped gzip to avoid this problem.
I don't know how autobuilders, etc, work, but I can imagine there may
be circumstances where it would be useful to be able to tell
immediately that a package was not changed when it was rebuilt after
installing a new version of some header file (or whatever) that might,
potentially, have caused the package to change. Or is this all
properly handled by some different mechanism that I can read about
somewhere?
Edmund
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