title: installing dotnet core in ubuntu end up having dependency conflicts
body: <p>I did install dotnetcore in ubuntu without any problem earlier. But sometime I end up having dependency issues with in earlier version but always with ubuntu 20.04.</p>
  <p>I am following the guidance provided <a href="https://docs.microsoft.com/en-us/dotnet/core/install/linux-package-manager-ubuntu-1910" rel="nofollow noreferrer">here</a></p>
  <p>Whenever I tried to install <code>sudo apt-get install dotnet-sdk-3.1</code> it shows dependency issues:</p>
  <blockquote>
  <p>The following packages have unmet dependencies:</p>
  <p>dotnet-sdk-3.1 : Depends: dotnet-runtime-3.1 (&gt;= 3.1.3) but it is not going to be installed</p>
  <p>Depends: aspnetcore-runtime-3.1 (&gt;= 3.1.3) but it is not going to be installed</p>
  <p>E: Unable to correct problems, you have held broken packages.</p>
  </blockquote>
  <p>I tried to add every packages one by one and eventually <code>sudo apt install dotnet-sdk-3.1 dotnet-runtime-3.1 aspnetcore-runtime-3.1 dotnet-runtime-deps-3.1</code>.</p>
  <pre><code>The following packages have unmet dependencies:
   dotnet-runtime-deps-3.1 : Depends: libicu but it is not installable or
                                      libicu63 but it is not installable or
                                      libicu60 but it is not installable or
                                      libicu57 but it is not installable or
                                      libicu55 but it is not installable or
                                      libicu52 but it is not installable
  </code></pre>
  <p>Now <code>apt-cache policy libicu</code> (or any libicu63 etc) show does not have installation candidate.</p>
  <blockquote>
  <p>libicu:<br />
  Installed: (none)<br />
  Candidate: (none)<br />
  Version table:</p>
  </blockquote>
  <p>I am not sure why is this happening and how to fix it.</p>