pbuilder ignoring additional repositories

[Motiejus Jakštys]

Hi,

I want to compile Iceweasel 10 (from testing) on Stable chroot using
some packages from debian-backports. This is what happens:

# apt-get source -t testing iceweasel
# pbuilder --build iceweasel_10.0.2-1.dsc
<...>
The following packages have unmet dependencies:
  pbuilder-satisfydepends-dummy: Depends: libcairo2-dev (>= 1.10.2-1.1~) but 1.8.10-6 is to be installed.
                                 Depends: libnspr4-dev (>= 4.8.8) but it is not going to be installed.
                                 Depends: libnss3-dev (>= 3.13.1) but it is not going to be installed.
                                 Depends: libsqlite3-dev (>= 3.7.7.1) but it is not going to be installed.
                                 Depends: libvpx-dev (>= 1.0.0) but it is not going to be installed.
Unable to resolve dependencies!  Giving up...

I am expecting pbuilder to use that dependencies. However, it complains.
From the chroot:

# apt-cache policy libnss3-dev
libnss3-dev:
  Installed: (none)
  Candidate: 3.12.8-1+squeeze4
  Version table:
     3.13.3-1~bpo60+1 0
        699 http://backports.debian.org/debian-backports/ squeeze-backports/main amd64 Packages
     3.12.8-1+squeeze4 0
        700 http://ftp.lt.debian.org/debian/ squeeze/main amd64 Packages

# apt-cache policy libnspr4-dev
libnspr4-dev:
  Installed: (none)
  Candidate: 4.8.6-1
  Version table:
     4.9-1~bpo60+1 0
        699 http://backports.debian.org/debian-backports/ squeeze-backports/main amd64 Packages
     4.8.6-1 0
        700 http://ftp.lt.debian.org/debian/ squeeze/main amd64 Packages


# cat /etc/apt/sources.list
deb http://ftp.lt.debian.org/debian squeeze main contrib non-free
deb-src http://ftp.lt.debian.org/debian squeeze main contrib non-free

deb http://backports.debian.org/debian-backports squeeze-backports main
contrib non-free
deb-src http://backports.debian.org/debian-backports squeeze-backports
main contrib non-free

deb http://127.0.0.1/ squeeze personal
deb-src http://127.0.0.1/ squeeze personal

# cat /etc/apt/preferences
Package: *
Pin: release a=stable
Pin-Priority: 700
Package: *
Pin: release a=squeeze-backports
Pin-Priority: 699

Why is pbuilder ignoring debian-backports? With 127.0.0.1/ same scenario
seems to go fine (dependencies are installed), but I would rather avoid
re-backporting things that are already backported.

Thanks,
Motiejus Jakštys