Конфликты зависимостей PostGIS (Ubuntu 14)

Я спросил об этом в SO, но теперь я думаю, что проблема в основном в управлении пакетами, и она здесь.

После всех деталей, которые можно найти в оригинальном посте, я попытался (sudo исключен как избыточный):

$ apt list | grep gdal | grep installed
gdal-bin/trusty,now 1.11.0+dfsg-1~exp2~trusty1 amd64 [installed]
libgdal1h/trusty,now 1.11.0+dfsg-1~exp2~trusty1 amd64 [installed,automatic]
$ apt-get purge gdal-bin
$ apt-get purge libdal1h
$ add-apt-repository ppa:ubuntugis/ppa
$ apt-get update
W: Failed to fetch http://ppa.launchpad.net/ubuntugis/ppa/ubuntu/dists/trusty/main/binary-amd64/Packages  404  Not Found

W: Failed to fetch http://ppa.launchpad.net/ubuntugis/ppa/ubuntu/dists/trusty/main/binary-i386/Packages  404  Not Found

так ясно, что что-то неправильно настроено ... Я не не знаю, что проверить на моей стороне ...

затем

$ fab vagrant.Provision # see the original question above for what this is doing at the linux level

Это все еще приводит к точно такой же проблеме зависимости libdal1 и libgdal1h:

[localhost] sudo: DEBIAN_FRONTEND=noninteractive apt-get install --quiet --assume-yes postgresql-9.3-postgis-2.1
[localhost] out: {...}
[localhost] out: Some packages could not be installed. This may mean that you have
[localhost] out: requested an impossible situation or if you are using the unstable
[localhost] out: distribution that some required packages have not yet been created
[localhost] out: or been moved out of Incoming.
[localhost] out: The following information may help to resolve the situation:
[localhost] out: 
[localhost] out: The following packages have unmet dependencies:
[localhost] out:  postgresql-9.3-postgis-2.1 : Depends: libgdal1 (>= 1.9.0) but it is not going to be installed
[localhost] out:                               Recommends: postgis but it is not going to be installed
[localhost] out: E: Unable to correct problems, you have held broken packages.

подробнее:

vagrant@ubuntu-14:~$ apt-cache policy postgresql-9.3-postgis-2.1
postgresql-9.3-postgis-2.1:
  Installed: (none)
  Candidate: 2.1.3+dfsg-3.pgdg12.4+2
  Version table:
     2.1.3+dfsg-3.pgdg12.4+2 0
        500 http://apt.postgresql.org/pub/repos/apt/ precise-pgdg/main amd64 Packages
     2.1.2+dfsg-2 0
        500 http://us.archive.ubuntu.com/ubuntu/ trusty/universe amd64 Packages