The unpacking message does note that you are installing the same version as was previously in place - which I guess is not surprising if you are trying to reinstall it. Given that this package is not vital for normal operation of the Pi I'd suggest:
sudo apt-get --fix-broken --reinstall install gitlab-ce
this does assume that nothing else is broken. If there ARE other issues I'm a great fan of using
aptitude rather than
apt-get; its interactive mode (uses ncurses-type screen and is the default if no command line arguments given) can be a help in working out what is/or will be going on when you type g (for "Go") to make the changes selected - in case it is not clear how to start there use Ctrl+t to access the menu line at the top.
EDIT: The OP reported that this was not enough, so I will suggest a "bigger-hammer":
sudo dpkg --force-depends --remove gitlab-ce
The first argument tells
dpkg (the underlying package manager that
aptitude talk with) to remove the package even if there are things that depend on it and that would be broken if it was taken away - this should be OK as we are aiming to put it back shortly.
Now we could try and remove the local copy of the package - just in case there was something funky about it - I would expect it to be located in the
/var/cache/apt/archives directory. You would be looking for a file called
gitlab-ce-XXX.deb where XXX is a version code of some sort.
Finally we can try again from scratch:
sudo apt-get install gitlab-ce
The following may be of help, in order they do:
sudo apt-get update - ensure we have an updated list of packages
sudo apt-get check - check the system for broken/missing packages
sudo apt-get -f install - repair anything reported by the previous check
Note: Reviewing the OP's link to the gitlab site - the step by step instructions talk about "2. Add the GitLab package server and install the package" however the command they provide creates a
gitlab_ce.list file in the correct
/etc/apt/sources.list.d/ directory with a reference to
jessie as the distribution version - I cannot help thinking that is an issue here considering the OP's assertion they are using Jessie - I'd follow that up with the package creators!