Sure, the issue is that the 100-continue packages you provide are not installable. This is due to apache 2.4 being the default and you providing 2.2 in the gitbuilder
2.4 is taking the preference and stopping fastcgi from being installed due to a hard dependency being set on 2.2
--
vagrant@base:~$ cat /etc/issue
Ubuntu 14.04 LTS \n \l
vagrant@base:~$ wget q -O https://raw.github.com/ceph/ceph/master/keys/autobuild.asc | sudo apt-key add -
OK
vagrant@base:~$ echo deb http://gitbuilder.ceph.com/apache2-deb-$(lsb_release -sc)-x86_64-basic/ref/master $(lsb_release -sc) main | sudo tee /etc/apt/sources.list.d/ceph-apache.list
deb http://gitbuilder.ceph.com/apache2-deb-trusty-x86_64-basic/ref/master trusty main
vagrant@base:~$ echo deb http://gitbuilder.ceph.com/libapache-mod-fastcgi-deb-$(lsb_release -sc)-x86_64-basic/ref/master $(lsb_release -sc) main | sudo tee /etc/apt/sources.list.d/ceph-fastcgi.list
deb http://gitbuilder.ceph.com/libapache-mod-fastcgi-deb-trusty-x86_64-basic/ref/master trusty main
vagrant@base:~$ sudo apt-get update && sudo apt-get install apache2 libapache2-mod-fastcgi
--->8--snip----
Fetched 27.2 MB in 9s (2,869 kB/s)
Reading package lists... Done
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
The following packages have unmet dependencies:
libapache2-mod-fastcgi : Depends: apache2.2-common (>= 2.2.4) but it is not going to be installed
E: Unable to correct problems, you have held broken packages.