How to install previous dotnet versions alongside latest versions?

Question

I'm using PopOs 21.10 and use the latest dotnet versions

Now I have to install the previous version dotnet core 3.1

I tried

wget https://packages.microsoft.com/config/ubuntu/21.04/packages-microsoft-prod.deb -O packages-microsoft-prod.deb

 sudo apt-get update; \
   sudo apt-get install -y apt-transport-https && \
   sudo apt-get update && \
   sudo apt-get install -y dotnet-sdk-3.1

but get the error

E: Unable to locate package dotnet-sdk-3.1

E: Couldn't find any package by glob 'dotnet-sdk-3.1'

I also tried to change the package name

 sudo apt-get update; \
   sudo apt-get install -y apt-transport-https && \
   sudo apt-get update && \
   sudo apt-get install -y aspnetcore-sdk-3.1

but get similiar errors. When downloading the tar archive I run these commands from inside the downloads directory

mkdir -p $HOME/dotnet && tar zxf dotnet-sdk-3.1.419-linux-arm64.tar.gz -C $HOME/dotnet
export DOTNET_ROOT=$HOME/dotnet
export PATH=$PATH:$HOME/dotnet

but even after restarting I can't find any 3.1 version on my machine. Would someone mind helping on how to install previous versions without removing other ones?

Answer 1

You should install the packages-microsoft-prod.deb file first.

wget https://packages.microsoft.com/config/ubuntu/21.04/packages-microsoft-prod.deb -O packages-microsoft-prod.deb
sudo dpkg -i packages-microsoft-prod.deb
sudo apt update
sudo apt install dotnet-sdk-3.1

Here is the output of apt policy dotnet-sdk-3.1:

Installed: (none)
  Candidate: 3.1.419-1
  Version table:
     3.1.419-1 500
        500 https://packages.microsoft.com/ubuntu/21.04/prod hirsute/main amd64 Packages
     3.1.418-1 500
        500 https://packages.microsoft.com/ubuntu/21.04/prod hirsute/main amd64 Packages
     3.1.417-1 500
        500 https://packages.microsoft.com/ubuntu/21.04/prod hirsute/main amd64 Packages
     3.1.416-1 500
        500 https://packages.microsoft.com/ubuntu/21.04/prod hirsute/main amd64 Packages
     3.1.415-1 500
        500 https://packages.microsoft.com/ubuntu/21.04/prod hirsute/main amd64 Packages
     3.1.414-1 500
        500 https://packages.microsoft.com/ubuntu/21.04/prod hirsute/main amd64 Packages
     3.1.413-1 500
        500 https://packages.microsoft.com/ubuntu/21.04/prod hirsute/main amd64 Packages
     3.1.412-1 500
        500 https://packages.microsoft.com/ubuntu/21.04/prod hirsute/main amd64 Packages
     3.1.411-1 500
        500 https://packages.microsoft.com/ubuntu/21.04/prod hirsute/main amd64 Packages
     3.1.410-1 500
        500 https://packages.microsoft.com/ubuntu/21.04/prod hirsute/main amd64 Packages
     3.1.409-1 500
        500 https://packages.microsoft.com/ubuntu/21.04/prod hirsute/main amd64 Packages
     3.1.408-1 500
        500 https://packages.microsoft.com/ubuntu/21.04/prod hirsute/main amd64 Packages
     3.1.120-1 500
        500 https://packages.microsoft.com/ubuntu/21.04/prod hirsute/main amd64 Packages
     3.1.119-1 500
        500 https://packages.microsoft.com/ubuntu/21.04/prod hirsute/main amd64 Packages
     3.1.118-1 500
        500 https://packages.microsoft.com/ubuntu/21.04/prod hirsute/main amd64 Packages
     3.1.117-1 500
        500 https://packages.microsoft.com/ubuntu/21.04/prod hirsute/main amd64 Packages
     3.1.116-1 500
        500 https://packages.microsoft.com/ubuntu/21.04/prod hirsute/main amd64 Packages
     3.1.115-1 500
        500 https://packages.microsoft.com/ubuntu/21.04/prod hirsute/main amd64 Packages
     3.1.114-1 500
        500 https://packages.microsoft.com/ubuntu/21.04/prod hirsute/main amd64 Packages

Installation guide: Install the .NET SDK or the .NET Runtime on Ubuntu

Manually adding Microsoft repository:

echo "deb [arch=amd64,arm64,armhf] https://packages.microsoft.com/ubuntu/21.04/prod hirsute main" |
sudo tee /etc/apt/sources.list.d/microsoft-prod.list
sudo apt update
sudo apt install dotnet-sdk-3.1