.NET 10 Installation troubleshooting on Ubuntu (Package dotnet-sdk-10.0 has no installation candidate)

[nickwb]

Type of issue

Other (describe below)

Description

Describe the issue or suggestion

Hi,

I recently had a rather difficult experience upgrading to .NET 10 on Ubuntu 24.04, and I thought I would share my experience in the hope that it could help others, and perhaps some documentation could be updated.

Backround

Somewhere in 2023 I was installing .NET 7 on my Ubuntu instance, and back at that time I believe the "officially endorsed" approach was to use the Microsoft package feed, and to ignore the packages published by canonical.

The documentation is still present today which recommends this:
https://github.com/dotnet/docs/blob/main/docs/core/install/linux-package-mixup.md#i-need-a-version-of-net-that-isnt-provided-by-my-linux-distribution

It recommends adding the following to /etc/apt/preferences:

Package: dotnet* aspnet* netstandard*
Pin: origin "archive.ubuntu.com"
Pin-Priority: -10

Three Years Later

Now 2026, I came to install .NET 10. The Microsoft Feed is no longer supported, and users are expected to use the packages published by canonical. The preferences that I had set three years prior made this very difficult.

The error I was getting was: E: Package dotnet-sdk-10.0 has no installation candidate

I had long since forgotten that I had blocked the canonical packages, and had to go through a significant amount of package manager debugging before I eventually rediscovered the erroneous /etc/apt/preferences that had been set previously.

I discovered this after running apt-cache policy and noticing that many dotnet packages were included under the "Pinned packages" section.

After removing the offending section from /etc/apt/preferences, I was able to install the package without issue.

Documentation Improvements

Perhaps on this page: https://learn.microsoft.com/en-us/dotnet/core/install/linux-ubuntu-install?tabs=dotnet10&pivots=os-linux-ubuntu-2404

A warning/note should be added that Microsoft has historically recommended blocking/disabling canonical packages, and that anyone who still has the configuration may encounter issues.

Page URL

https://learn.microsoft.com/en-us/dotnet/core/install/linux-ubuntu-install

Content source URL

https://github.com/dotnet/docs/blob/live/docs/core/install/linux-ubuntu-install.md

Document Version Independent Id

e7286112-86cf-8d6a-655b-ee851f396d15

Article author

adegeo

Metadata

• ID: 72799d86-e122-1706-18a2-d0bfde699bfc
• Service: dotnet-fundamentals
• Sub-service: install

[adegeo]

Hello! Ack, I'm sorry you had that difficult upgrade. It's situations like this that caused us to start working with Canonical to releasing .NET for Ubuntu instead of Microsoft. And starting with .NET 9, we no longer publish packages for distributions that publish their own .NET packages.

Regarding your specific situation, I'm pretty sure that we didn't release any packages in the Microsoft package repository for 24.XX. It sounds like what you actually did was upgrade 23.XX (or 22.XX) to 24.XX. We have a section in the install guide that says you should uninstall .NET first because it puts you in a bad state. But it's not as if you're going to go consult that article when you're looking at upgrading your OS.... It's the chicken and the egg problem.

The problem you ran into used to be more common than it is now. As time goes on, it will eventually phase itself out.

I'm going to close this issue as I don't think I'm going to update anything, however, I'll keep your issue in mind and if I see others running into the same issue, I'll look at improvement to documentation somehow. But right now, I don't think it's very common to get in this state.