Broken libglib on debian 6
 

So, some time ago I wanted to update mpd to the newest version which required a newer version of libglib, so I compiled them from source as I was on debian oldstable and couldn't find an easier way of doing that. For various reasons I didn't have access to that system again until now. When I tried to run mpd it gave me the following error:

I tried reinstalling mpd but to no result, so then I tried to reinstall libglib but it gave me the following output:

Because I didn't have access to the system for some time, I don't really remember what I did back then and I'm not sure how to revert it.

Can you post the contents of your /etc/apt/sources.list file.
You are clearly having dependency issues as you can see from the error messages. Is there any reason for using such an old version of Debian? In any event you can get the oldstable version of libglib2.0 which is version 2.24.2-1 so you don't really need to compile it from source.
jdk

The reason I still have oldstable is because I'm using OpenMediaVault. Here's my sources file:

OpenMediaVault makes the following claim:
So can you explain why you are compiling these packages yourself rather than following their advice. You can install the version you wish using the normal package management.
jdk

Well, the thing is I wanted mpd 1.6 which required libglib >= 2.31.8 on amd64, which I couldn't get via apt-get, as oldstable goes up to 2.24.2.

I can't do that. When I tried that, it gave the errors in the first post. I have tried apt-get check to fix any broken deps but apt doesn't seem to find any.

But in your first post you presented a reinstall. So that means the package was already installed. Why did you want to reinstall it?
jdk

I'm sorry, I wasn't clear. Having mpd installed I had libglib installed too. My first attempt was to try and install libglib but apt tried to install some additional libglib packages (such as libglib2.0-dev or libglib2.0-doc) and reported libglib to be at the newest version, also giving me the following error which is very similar with the one from the reinstall:

The installation failed of course giving output very similar to the output given by the reinstall.

And does your system now report broken packages? If so, which ones?
jdk

apt-get check doesn't return anything. I should mention that I just found some libglib files in /usr/local/lib and I suspect they may be from me.

Yes, if "from me" means "files that are the result of your own compilation. You can always try to remove the broken packages and then install them (not reinstall) them.
jdk

I would do that, but a lot of stuff depends on glib, and removing it would remove them too. Is there any way to remove the problematic packages without removing everything that depends on them?

You can do a simulation (in aptitude it's the -s option) of removing glib without actually removing it. That will give you an idea of what other packages would be removed. It's not a big deal to copy that list and then paste it back into a future command installing all the files that were removed when you removed glib.
jdk

Just to make sure, removing the packages won't delete their settings, right?

So I tried removing libglib, but this happened:

So I identified libglib2.0-cil as the troublemaker, and after some googling I manually removed it with:

Then I tried reinstalling all the removed packages but this happened:

It should be noted, that even after removing libglib, the custom version I compiled was still in /usr/local/lib. Is there any way to remove it?

That is the difference between "remove" and "purge". Remove doesn't remove the settings; purge removes everything including the settings.
jdk