Unable to install mysql-workbench for Ubuntu 16.04 LTS

It seems that you forgot to run sudo apt-get update before installing MySQL Workbench (Australian mirror is synced normally, it has correct version of gcc-5-base in pool).

If it does not help, try to switch to Main server (Software & Updates or software-properties-gtk, Ubuntu Software tab, set Download from to Main server).

For sure add all official repositories with:

sudo add-apt-repository main
sudo add-apt-repository universe
sudo add-apt-repository multiverse

Make sure you have enabled xenial-updates and xenial-security sections:

1. open software-properties-gtk
2. go to Updates tab
3. check first two checkboxes - (xenial-updates) and (xenial-security)
4. enter password, click Authenticate
5. click Close, then Reload and wait it to finish.

Then run

sudo apt-get update   
sudo apt-get install -f
sudo apt-get upgrade
sudo apt-get dist-upgrade
sudo apt-get install mysql-workbench

Thanks for aptitude. Finally I worked it out after referring to octave installed error - Depends: gcc-5-base (= 5.3.1-14ubuntu2) . aptitude will propose multiple solutions after you continuously input n. Choose the one with the downgrade packages. Everything works as charming.

The following packages have unmet dependencies: libgfortran3 : Depends: gcc-5-base (= 5.3.1-14ubuntu2) but 5.4.0-6ubuntu1~16.04.1 is installed. mysql-connector-python : Conflicts: python-mysql.connector but 2.0.4-1 is to be installed. The following actions will resolve these dependencies:

  Keep the following packages at their current version:

1) libarmadillo6 [Not Installed]
2) libarpack2 [Not Installed]
3) libgdal1i [Not Installed]
4) libgfortran3 [Not Installed]
5) libhdf5-10 [Not Installed]
6) liblapack3 [Not Installed]
7) libnetcdf11 [Not Installed]
8) mysql-connector-python [Not Installed]
9) mysql-utilities [Not Installed]
10) mysql-workbench [Not Installed]

Accept this solution? [Y/n/q/?] n The following actions will resolve these dependencies:

 Keep the following packages at their current version:

1) libarmadillo6 [Not Installed]
2) libarpack2 [Not Installed]
3) libgdal1i [Not Installed]
4) libgfortran3 [Not Installed]
5) libhdf5-10 [Not Installed]
6) liblapack3 [Not Installed]
7) libnetcdf11 [Not Installed]
8) mysql-workbench [Not Installed]
9) python-mysql.connector [Not Installed]

Accept this solution? [Y/n/q/?] n The following actions will resolve these dependencies:

  Remove the following packages:                                           

1) build-essential
2) g++
3) g++-5
4) gcc
5) gcc-5
6) libasan2
7) libatomic1
8) libcilkrts5
9) libgcc-5-dev
10) libitm1
11) liblsan0
12) libmpx0
13) libstdc++-5-dev
14) libtsan0
15) libubsan0

  Install the following packages:                                          

16) mysql-utilities [1.6.1-2 (xenial)]
17) tcc [0.9.27~git20151227.933c223-1 (xenial)]

  Keep the following packages at their current version:                    

18) mysql-connector-python [Not Installed]

  Downgrade the following packages:                                        

19) cpp-5 [5.4.0-6ubuntu1~16.04.1 (now) -> 5.3.1-14ubuntu2 (xenial)]
20) gcc-5-base [5.4.0-6ubuntu1~16.04.1 (now) -> 5.3.1-14ubuntu2 (xenial)]
21) libcc1-0 [5.4.0-6ubuntu1~16.04.1 (now) -> 5.3.1-14ubuntu2 (xenial)]
22) libgomp1 [5.4.0-6ubuntu1~16.04.1 (now) -> 5.3.1-14ubuntu2 (xenial)]
23) libquadmath0 [5.4.0-6ubuntu1~16.04.1 (now) -> 5.3.1-14ubuntu2 (xenial)] 24) libstdc++6 [5.4.0-6ubuntu1~16.04.1 (now) -> 5.3.1-14ubuntu2 (xenial)]

  Leave the following dependencies unresolved:                             

25) dpkg-dev recommends build-essential

Accept this solution? [Y/n/q/?] The following packages will be DOWNGRADED: cpp-5 gcc-5-base libcc1-0 libgomp1 libquadmath0 libstdc++6