12.0 fresh install: sh setup.sh tries and fails to install developer tools

[root@tikisuite 12]# sh setup.sh

 Tiki setup.sh - your options
 ============================

 c run composer and exit (recommended to be done first)

 f fix (classic default)                 o open (classic option)
 S clear screen

 predefined Tiki Permission Check models:
 ----------------------------------------

 1 paranoia
 2 paranoia-suphp                        w suphp workaround
 3 sbox                                  W sbox workaround
 4 mixed
 5 worry                                 6 moreworry
 7 pain                                  8 morepain
 9 risky                                 a insane

 q quit                                  x exit

There are some other commands recommended for advanced users only.
More documentation about this: http://doc.tiki.org/Permission+Check

Your choice [c]?
#!/usr/bin/env php
Some settings on your machine may cause stability issues with Composer.
If you encounter issues, try to change the following:

Your PHP (5.3.3) is quite old, upgrading to PHP 5.3.4 or higher is recommended.
Composer works with 5.3.2+ for most people, but there might be edge case issues.

Downloading...

Composer successfully installed to: /var/www/html/12/temp/composer.phar
Use it: php temp/composer.phar
Loading composer repositories with package information
Installing dependencies (including require-dev) from lock file
Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - phpunit/phpunit 3.7.28 requires ext-dom * -> the requested PHP extension d                                                                                        om is missing from your system.
    - phpunit/phpunit 3.7.28 requires ext-dom * -> the requested PHP extension d                                                                                        om is missing from your system.
    - Installation request for phpunit/phpunit 3.7.28 -> satisfiable by phpunit/                                                                                        phpunit[3.7.28].

Composer failed, retrying in 5 seconds, for a few times. Hit Ctrl-C to cancel.
Loading composer repositories with package information
Installing dependencies (including require-dev) from lock file
Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - phpunit/phpunit 3.7.28 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 3.7.28 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - Installation request for phpunit/phpunit 3.7.28 -> satisfiable by phpunit/phpunit[3.7.28].

Composer failed, retrying in 5 seconds, for a few times. Hit Ctrl-C to cancel.
Loading composer repositories with package information
Installing dependencies (including require-dev) from lock file
Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - phpunit/phpunit 3.7.28 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 3.7.28 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - Installation request for phpunit/phpunit 3.7.28 -> satisfiable by phpunit/phpunit[3.7.28].

Composer failed, retrying in 5 seconds, for a few times. Hit Ctrl-C to cancel.
Loading composer repositories with package information
Installing dependencies (including require-dev) from lock file
Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - phpunit/phpunit 3.7.28 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 3.7.28 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - Installation request for phpunit/phpunit 3.7.28 -> satisfiable by phpunit/phpunit[3.7.28].

Composer failed, retrying in 5 seconds, for a few times. Hit Ctrl-C to cancel.
Loading composer repositories with package information
Installing dependencies (including require-dev) from lock file
Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - phpunit/phpunit 3.7.28 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 3.7.28 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - Installation request for phpunit/phpunit 3.7.28 -> satisfiable by phpunit/phpunit[3.7.28].

Composer failed, retrying in 5 seconds, for a few times. Hit Ctrl-C to cancel.
Loading composer repositories with package information
Installing dependencies (including require-dev) from lock file
Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - phpunit/phpunit 3.7.28 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 3.7.28 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - Installation request for phpunit/phpunit 3.7.28 -> satisfiable by phpunit/phpunit[3.7.28].

Composer failed, retrying in 5 seconds, for a few times. Hit Ctrl-C to cancel.
Loading composer repositories with package information
Installing dependencies (including require-dev) from lock file
Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - phpunit/phpunit 3.7.28 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 3.7.28 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - Installation request for phpunit/phpunit 3.7.28 -> satisfiable by phpunit/phpunit[3.7.28].