Comment 5 for bug 1368819

ubuntu@trusty:~$ virt-builder --list
virt-builder: curl is not installed (or does not work)
ubuntu@trusty:~$ sudo apt-get install libguestfs-tools
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following extra packages will be installed:
  curl libguestfs-perl libguestfs0
The following NEW packages will be installed:
  curl
The following packages will be upgraded:
  libguestfs-perl libguestfs-tools libguestfs0
3 upgraded, 1 newly installed, 0 to remove and 26 not upgraded.
Need to get 3,569 kB of archives.
After this operation, 315 kB of additional disk space will be used.
Do you want to continue? [Y/n]
Get:1 http://nova.clouds.archive.ubuntu.com/ubuntu/ trusty-proposed/universe libguestfs-tools amd64 1:1.24.5-1ubuntu0.1 [2,529 kB]
Get:2 http://nova.clouds.archive.ubuntu.com/ubuntu/ trusty-proposed/universe libguestfs-perl amd64 1:1.24.5-1ubuntu0.1 [268 kB]
Get:3 http://nova.clouds.archive.ubuntu.com/ubuntu/ trusty-updates/main curl amd64 7.35.0-1ubuntu2.5 [123 kB]
Get:4 http://nova.clouds.archive.ubuntu.com/ubuntu/ trusty-proposed/universe libguestfs0 amd64 1:1.24.5-1ubuntu0.1 [649 kB]
Fetched 3,569 kB in 0s (14.3 MB/s)
Preconfiguring packages ...
(Reading database ... 102152 files and directories currently installed.)
Preparing to unpack .../libguestfs-tools_1%3a1.24.5-1ubuntu0.1_amd64.deb ...
Unpacking libguestfs-tools (1:1.24.5-1ubuntu0.1) over (1:1.24.5-1) ...
Preparing to unpack .../libguestfs-perl_1%3a1.24.5-1ubuntu0.1_amd64.deb ...
Unpacking libguestfs-perl (1:1.24.5-1ubuntu0.1) over (1:1.24.5-1) ...
Selecting previously unselected package curl.
Preparing to unpack .../curl_7.35.0-1ubuntu2.5_amd64.deb ...
Unpacking curl (7.35.0-1ubuntu2.5) ...
Preparing to unpack .../libguestfs0_1%3a1.24.5-1ubuntu0.1_amd64.deb ...
Unpacking libguestfs0:amd64 (1:1.24.5-1ubuntu0.1) over (1:1.24.5-1) ...
Processing triggers for man-db (2.6.7.1-1ubuntu1) ...
Setting up libguestfs0:amd64 (1:1.24.5-1ubuntu0.1) ...
Setting up libguestfs-perl (1:1.24.5-1ubuntu0.1) ...
Setting up curl (7.35.0-1ubuntu2.5) ...
Setting up libguestfs-tools (1:1.24.5-1ubuntu0.1) ...
Processing triggers for libc-bin (2.19-0ubuntu6.6) ...
ubuntu@trusty:~$ virt-builder --list
virt-builder: index is corrupt: os-version 'fedora-21' appears two or more times

The index file downloaded from 'http://libguestfs.org/download/builder/index.asc' is corrupt.
You need to ask the supplier of this file to fix it and upload a fixed version.
ubuntu@trusty:~$

Not good, but not worse.