Re: pbuilder, and why not...

["Bernhard R. Link" <brlink@debian.org>]

* Dirk Eddelbuettel <edd@debian.org> [060514 18:54]:
> e) yes, it may add a minute here or there, but pbuilder _dramatically_ 
> increases your build reliability and saves you and the admins time as it 
> prevents (build) bugs from propagating.  Also, with proper uses of LVM and 
> snapshotting, you could reduce that time to very little or none.

While chrooted buildds make the generated binaries much more reliable,
it removes an important test case for the source packages. Debian source
packages are supposed to also work correctly when run in an unclean
build environment.
You'll never catch some kind of errors when only building in minimal
chroots:
        - stupid autodetection switching on additional features
        when some special program or library is installed.
        (bug in debian/rules for not giving the appropiate --without-foo
         or bug in upstream for not offering such a switch)
        - install rules not installing something to $DESTDIR when
        it is already installed in the final place.
        (bug in upstream, or bug you introduced when adding DESTDIR
         support)
        - incompatibility against alternate build dependencies or 
        (more likely) against some combination of alternate dependencies
        of build dependencies or even of dependencies of
        build-dependencies.
        
All of these can happen and do happen from time to time, but only show
up once someone tries to compile it on his own or the buildd tried the
wrong package before this.
Thus make sure to compile your packages from time to time in a real
environment and compare the contents. (It's good to test installation,
upgrade and removal an a real system, too, so that might also catch
suprises when the package it already installed while building)

Hochachtungsvoll,
  Bernhard R. Link