I asked this over on SO, but now I'm thinking the problem is mainly package management and belongs here.

Subsequent to all the detail that can be found in the original post, I have tried (sudo eliminated as redundant):

$ 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

so clearly something is misconfigured... I don't know what to check for on my side...

then

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

This still runs into the exact same libdal1 v. libgdal1h dependency issue:

[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.

more info :

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