Why can't I install g++?

Question

while trying to compile a program with the following command: g++ -o <output_file> <my_file.cpp>

I found the following report....

The program 'g++' can be found in the following packages:
 * g++
 * pentium-builder
 Try: sudo apt-get install <selected package>

Then I tried...

nawshad@ubuntu:~/Thesis/Codes/Thesis_Utility_Function/Test Codes$ sudo apt-get   install   g++
Reading package lists... Done
Building dependency tree       
Reading state information... Done
You might want to run 'apt-get -f install' to correct these:
The following packages have unmet dependencies:
 g++ : Depends: g++-4.6 (>= 4.6.3-1~) but it is not going to be installed
 libqt4-opengl : Depends: libqtcore4 (= 4:4.8.1-0ubuntu4.1) but 4:4.8.1-0ubuntu4 is to be installed
                 Depends: libqtgui4 (= 4:4.8.1-0ubuntu4.1) but 4:4.8.1-0ubuntu4 is to be installed
 libqt4-svg : Depends: libqtcore4 (= 4:4.8.1-0ubuntu4.1) but 4:4.8.1-0ubuntu4 is to be installed
              Depends: libqtgui4 (= 4:4.8.1-0ubuntu4.1) but 4:4.8.1-0ubuntu4 is to be installed
E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution).

But cant install due to unmet dependencies.

Solution

Run:

sudo apt-get update

You should always run that before installing or upgrading packages on the command-line (unless you've run it very recently). It fetches information about what packages are available in what versions from where.

You may simply be able to install g++ now, but go ahead and do as Web-E says (after running the above command), to fix any currently broken dependencies:

sudo apt-get -f install

(The -f can actually go before or after the install; the effect is the same.)

Then try installing g++ again:

sudo apt-get install g++

If that still fails, please edit your question to show any error messages (and also the output of the above two commands when you ran them). But it should succeed.

Comments

[Admin]

Run sudo apt-get install -f

[Admin]

If my answer didn't solve this (or for anyone for whom it didn't), I suspect this is actually a duplicate of Problem installing g++ ccompiler on Ubuntu 14.04, since the indicated qt packages really shouldn't be dependencies of g++ at all, suggesting g++ may be being interpreted as a pattern by apt-get (which happens when the package manager doesn't know about the existence of a package called g++ due to repositories being disabled).

[MiNdFrEaK]

while updating following error occurs: nawshad@ubuntu:~$ sudo apt-get update [sudo] password for nawshad: E: Could not get lock /var/lib/apt/lists/lock - open (11: Resource temporarily unavailable) E: Unable to lock directory /var/lib/apt/lists/ E: Could not get lock /var/lib/dpkg/lock - open (11: Resource temporarily unavailable) E: Unable to lock the administration directory (/var/lib/dpkg/), is another process using it?

[Eliah Kagan]

@MiNdFrEaK Do you have other open package management programs, like the Update Manager, the Software Center, Synaptic, or another running instance of apt-get? (Also, in the future, to share output from the command-line, you should edit your question; usually it is very difficult to read it without proper formatting, which it almost never has when posted in a comment.)

[MiNdFrEaK]

Sorry, I am very new in this group, I'll edit my question at later comments, yes I do have, its Ubuntu Software Center.

[Eliah Kagan]

@MiNdFrEaK Quit the Software Center and try running those commands again. This should eliminate the Could not get lock errors.

[MiNdFrEaK]

Now,after updating, I ran the above commands serially, but the unmet dependencies are not resolved.

[Eliah Kagan]

@MiNdFrEaK Please try Steps 1-5 of this procedure. That may solve your problem. If not, please edit your question to provide all the text from the Terminal, from Step 5.

[FindOutIslamNow]

@EliahKagan Thank you guy.. Your answer was very useful for me