Can't install dependencies in Ubuntu to run FBC. Why? :S

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xlucas
Posts: 334
Joined: May 09, 2014 21:19
Location: Argentina

Can't install dependencies in Ubuntu to run FBC. Why? :S

Post by xlucas »

I've install FB on my computer many times and with this same exact distro of xubuntu, I've already done it a few months ago. Now I'm doing it again and for some strange reason, I can no longer install some of the dependencies. This is what I get:

Code: Select all

xlucas@xlucas:~$ sudo apt-get install libXext-dev
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:
 libxext-dev : Depends: libxext6 (= 2:1.3.2-1) but 2:1.3.2-1ubuntu0.0.14.04.1 is to be installed
E: Unable to correct problems, you have held broken packages.
Looks like Ubuntu has an alternative for this lib? I don't understand. Is the alternative installed and I should remove it or is it not and I should tell the system to bypass it somehow? Got lost. Like we say here, "my books are burnt". Help, please!

(I get similar errors with Xrandr and Xrender... I think it's because I'm missing this one lib).
counting_pine
Site Admin
Posts: 6323
Joined: Jul 05, 2005 17:32
Location: Manchester, Lancs

Re: Can't install dependencies in Ubuntu to run FBC. Why? :S

Post by counting_pine »

Not sure, but I think I've seen problems like this before..
Does this answer help at all?
http://askubuntu.com/a/142808/37574
xlucas
Posts: 334
Joined: May 09, 2014 21:19
Location: Argentina

Re: Can't install dependencies in Ubuntu to run FBC. Why? :S

Post by xlucas »

Thanks, counting_pine. Actually, my distro was just installed and the procedures there seemed to assume that my apt-get was broken because of some new PPA I would have added or something. I kept on researching and found that other people had this same problem and most solutions posted were kind of like "do this, then that" and nobody understood why. Finally, I solved the problem by learning to understand what was going on. Here's what I did, in case it helps anybody else:

- What apt-get was telling me was very cryptic, so I was not understanding. What it meant was that the package I was trying to install required another package that was installed, but this dependency currently was a version newer than the one my package required. So the solution had to be to either install anyway and see if it worked (but apt-get was not letting me do that), or downgrade the dependency (but I didn't know how to get apt-get to do that) or to find a new version of the package I was trying to install (which I had no idea if it existed and if it did, how to get it). At least, I knew which options I had, although I admit, I didn't know which was the preferable one.

- I found a forum thread of a guy with a similar problem and another recommending aptitude instead of apt-get. So I downloaded aptitude (sudo apt-get install aptitude) and ran it (sudo aptitude - as a non-root, I couldn't change anything). Aptitude explained me verbosely what was happening and suggested me a downgrade of the dependency. I did that. It worked :)
srvaldez
Posts: 3373
Joined: Sep 25, 2005 21:54

Re: Can't install dependencies in Ubuntu to run FBC. Why? :S

Post by srvaldez »

xlucas wrote: Aptitude explained me verbosely what was happening and suggested me a downgrade of the dependency. I did that. It worked :)
I am curious as to how you did the downgrade, care to share?
xlucas
Posts: 334
Joined: May 09, 2014 21:19
Location: Argentina

Re: Can't install dependencies in Ubuntu to run FBC. Why? :S

Post by xlucas »

Well, I'll try to explain.

I read that aptitude is a front-end for apt. I am not very skilled at using apt... I just do apt-get install when I want to install something and sometimes apt-get update. That's it. So when I read advice suggesting to use this tool, I installed it (via sudo apt-get install aptitude). Then I ran it by typing sudo aptitude in the console.
When you run aptitude, you get a list of the packages known by it. Some installed and some (most) not. You can use the mouse to click on the menus if you're using a virtual console. I don't know how to open up the menus otherwise, but you can press the forward slash "/" to search for a package. You get a string field and you can start typing the name of the package you want to install. I typed in the name of the package I had problems installing (I think it was libxrandr-dev first. The package name appeared marked as not installed. I pressed Enter, which landed me on the package name. I pressed "i", which marked it pending to be installed. Then I pressed "g", which performs the changes. Aptitude responded telling me that one of the dependencies was installed but was a newer version. When I insisted, it gave me one possible solution: downgrade. And then "no more options". So I chose downgrade. And it did that and installed xrandr.
It's a lot more straightforward that using apt alone, but still, the interface is not very comfortable. Shortcuts are not obvious and, while you can find information on them (by hitting the question mark), one tends nowaday to assume that certain keys will do certain things (like Esc will go to the previous screen) and they don't. Worse... they may actually do something else.
counting_pine
Site Admin
Posts: 6323
Joined: Jul 05, 2005 17:32
Location: Manchester, Lancs

Re: Can't install dependencies in Ubuntu to run FBC. Why? :S

Post by counting_pine »

You could maybe try using synaptic. It sounds like it's basically a GUI version of aptitude. It's a little bare-bones, but I much prefer it to the Ubuntu Software Center.
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