{"id":3912,"date":"2026-04-23T18:12:39","date_gmt":"2026-04-23T18:12:39","guid":{"rendered":"https:\/\/rssfeedtelegrambot.bnaya.co.il\/index.php\/2026\/04\/23\/whats-new-for-net-in-ubuntu-26-04\/"},"modified":"2026-04-23T18:12:39","modified_gmt":"2026-04-23T18:12:39","slug":"whats-new-for-net-in-ubuntu-26-04","status":"publish","type":"post","link":"https:\/\/rssfeedtelegrambot.bnaya.co.il\/index.php\/2026\/04\/23\/whats-new-for-net-in-ubuntu-26-04\/","title":{"rendered":"What\u2019s new for .NET in Ubuntu 26.04"},"content":{"rendered":"

Today is launch day for Ubuntu 26.04<\/a> (Resolute Raccoon<\/a>). Congratulations on the release to our friends at Canonical. Each new Ubuntu LTS comes with the latest .NET LTS so that you can develop and run .NET apps easily. Ubuntu 26.04 comes with .NET 10. You can also install .NET 8 and 9 via a separate PPA\/feed. Installation instructions are demonstrated later in the post. .NET is one of the officially supported toolchains<\/a> on Ubuntu. The two companies work together to ensure that .NET works well on Ubuntu.<\/p>\n

To install .NET 10:<\/p>\n

sudo apt update\r\nsudo apt install dotnet-sdk-10.0<\/code><\/pre>\n
Ubuntu 26.04 container images<\/a> are also available for .NET 10+, released earlier this month. They use the resolute<\/code> tag. You can update -noble<\/code> tags to -resolute<\/code> to upgrade to the new OS.<\/p>\n
Ubuntu 26.04 release notes<\/a> describe many changes. The most relevant changes are Linux 7.0<\/a>, post-quantum cryptography, and removal of cgroup v1 (container-related)<\/a>. We will start Linux 7.0 testing once we get Ubuntu 26.04 VMs in our lab, shortly. We added support for post-quantum cryptography<\/a> in .NET 10. We added support for cgroup v2<\/a> many years ago so cgroup v1 removal should be a non-event.<\/p>\n
We\u2019ve been on the \u201croad to next Ubuntu LTS\u201d since early 2025 when we started testing Debian 13 and Ubuntu 24.10 in CI. We started testing 26.04 in late 2025. Every PR in dotnet\/runtime<\/a> runs validation on Ubuntu 26.04. It\u2019s possible that our repo is one of the biggest users of Ubuntu 26.04 container images, at least up until today. Ubuntu standard releases (24.10, 25.04, \u2026) invariably require some level of change on our part, which is all part of being ready for GA day.<\/p>\n
Installing .NET 10<\/h2>\n
I\u2019ll demonstrate installing .NET 10 in an ubuntu:resolute<\/code> container image.<\/p>\n
$ docker run --rm -it ubuntu:resolute\r\n$ apt update\r\n$ apt install -y dotnet-sdk-10.0\r\n$ dotnet --version\r\n10.0.105<\/code><\/pre>\n
Let\u2019s run some C#.<\/p>\n
$ dotnet run - << 'EOF'\r\nusing System.Runtime.InteropServices;\r\n\r\nConsole.WriteLine($\"Hello {RuntimeInformation.OSDescription} from .NET {RuntimeInformation.FrameworkDescription}\");\r\nEOF\r\nHello Ubuntu Resolute Raccoon (development branch) from .NET .NET 10.0.5<\/code><\/pre>\n
\u201cRun some C#\u201d. That\u2019s funny wording. The example above is file-based app<\/a> constructed via a heredoc<\/a> and passed to dotnet run<\/code> via stdin<\/code>. Standard unix patterns at play. If you watch closely, AI agents love to do the same thing in Python. Don\u2019t hesitate to tell them that it works great with C# as well!<\/p>\n
Containers<\/h2>\n
The new resolute<\/code> images will be much the same as noble<\/code> ones. There is no change in the image flavors we offer, like Chiseled<\/a>. Recall that containers rely on the kernel of the host. For example, a 26.04 container hosted on a 24.04 host (as is the case in my examples) will be using Linux kernel 6.x.<\/p>\n
Let\u2019s try running our aspnetapp sample<\/a>.<\/p>\n
We first need to migrate the sample.<\/p>\n
$ grep dotnet\/ Dockerfile.chiseled\r\n# https:\/\/github.com\/dotnet\/dotnet-docker\/blob\/main\/samples\/README.md\r\nFROM --platform=$BUILDPLATFORM mcr.microsoft.com\/dotnet\/sdk:10.0-noble AS build\r\nFROM mcr.microsoft.com\/dotnet\/aspnet:10.0-noble-chiseled\r\n$ sed -i \"s\/noble\/resolute\/g\" Dockerfile.chiseled<\/code><\/pre>\n
And now to build and run it, with resource limits<\/a>.<\/p>\n
docker build --pull -t aspnetapp -f Dockerfile.chiseled .\r\ndocker run --rm -it -p 8000:8080 -m 50mb --cpus .5 aspnetapp<\/code><\/pre>\n
\"Welcome<\/p>\n
Native AOT<\/h2>\n
Native AOT (NAOT)<\/a> is a great choice when you want a fast to start self-contained native binary. The -aot<\/code> variant package gives you most of what you need. I publish all my tools as RID-specific tools<\/a>. That\u2019s outside the scope of this post. Let\u2019s focus on the basics. I\u2019ll use ubuntu:resolute<\/code> again.<\/p>\n
Here\u2019s the dotnet-sdk-aot-10.0<\/a> package, among the other SDK packages:<\/p>\n
$ apt list dotnet-sdk*\r\ndotnet-sdk-10.0-source-built-artifacts\/resolute 10.0.105-0ubuntu1 amd64\r\ndotnet-sdk-10.0\/resolute,now 10.0.105-0ubuntu1 amd64 [installed,automatic]\r\ndotnet-sdk-aot-10.0\/resolute,now 10.0.105-0ubuntu1 amd64 [installed]\r\ndotnet-sdk-dbg-10.0\/resolute 10.0.105-0ubuntu1 amd64<\/code><\/pre>\n
We need the AOT package + clang<\/code> (.NET uses LLD for linking):<\/p>\n
apt install -y dotnet-sdk-aot-10.0 clang<\/code><\/pre>\n
I\u2019ll publish the same hello world app (written to a file this time) as NAOT (the default for file-based apps).<\/p>\n
$ dotnet publish app.cs\r\n$ du -h artifacts\/app\/*\r\n1.4M    artifacts\/app\/app\r\n3.0M    artifacts\/app\/app.dbg<\/code><\/pre>\n
The binary is 1.4 MB. The .dbg<\/code> file is a native symbols file, much like Windows PDB. The minimum NAOT binary is about 1.0 MB. The use of the RuntimeInformation<\/code> class brings in more code.<\/p>\n
Let\u2019s check out the startup performance.<\/p>\n
$ time .\/artifacts\/app\/app\r\nHello Ubuntu Resolute Raccoon (development branch) from .NET .NET 10.0.5\r\n\r\nreal    0m0.003s\r\nuser    0m0.001s\r\nsys     0m0.001s<\/code><\/pre>\n
Pretty good! That\u2019s 3 milliseconds.<\/p>\n
NAOT works equally well for web services. Let\u2019s take a look at our releasesapi<\/a> sample.<\/p>\n
$ grep Aot releasesapi.csproj\r\n    <PublishAot>true<\/PublishAot>\r\n$ dotnet publish\r\n$ du -h bin\/Release\/net10.0\/linux-x64\/publish\/*\r\n4.0K    bin\/Release\/net10.0\/linux-x64\/publish\/NuGet.config\r\n4.0K    bin\/Release\/net10.0\/linux-x64\/publish\/appsettings.Development.json\r\n4.0K    bin\/Release\/net10.0\/linux-x64\/publish\/appsettings.json\r\n13M     bin\/Release\/net10.0\/linux-x64\/publish\/releasesapi\r\n32M     bin\/Release\/net10.0\/linux-x64\/publish\/releasesapi.dbg\r\n4.0K    bin\/Release\/net10.0\/linux-x64\/publish\/releasesapi.staticwebassets.endpoints.json\r\n$ .\/bin\/Release\/net10.0\/linux-x64\/publish\/releasesapi\r\ninfo: Microsoft.Hosting.Lifetime[14]\r\n      Now listening on: http:\/\/localhost:5000\r\ninfo: Microsoft.Hosting.Lifetime[0]\r\n      Application started. Press Ctrl+C to shut down.\r\ninfo: Microsoft.Hosting.Lifetime[0]\r\n      Hosting environment: Production\r\ninfo: Microsoft.Hosting.Lifetime[0]\r\n      Content root path: \/dotnet-docker\/samples\/releasesapi<\/code><\/pre>\n
In another terminal:<\/p>\n
$ curl -s http:\/\/localhost:5000\/releases | jq '[.versions[] | select(.supported == true) | {version, supportEndsInDays}]'\r\n[\r\n  {\r\n    \"version\": \"10.0\",\r\n    \"supportEndsInDays\": 942\r\n  },\r\n  {\r\n    \"version\": \"9.0\",\r\n    \"supportEndsInDays\": 207\r\n  },\r\n  {\r\n    \"version\": \"8.0\",\r\n    \"supportEndsInDays\": 207\r\n  }\r\n]<\/code><\/pre>\n
Note: jq<\/code><\/a> is an excellent tool that is basically \u201cLINQ over JSON\u201d. It takes JSON and enables generating new JSON with the analog of anonymous types.<\/p>\n
That\u2019s a 13 MB self-contained web service including a lot of source-generated System.Text.Json<\/a> metadata and code.<\/p>\n
Installing .NET 8 and 9<\/h2>\n
Our partners at Canonical make a hard separation between support and availability. .NET 8 and 9 are provided via the dotnet-backports PPA feed<\/a>. These sometimes older, sometimes newer, versions are offered with \u201cbest-effort support\u201d. We expect that .NET 11 will be added to this same PPA at GA.<\/p>\n
The software-properties-common<\/code> package is required to configure the feed. It is typically pre-installed on desktop versions of Ubuntu.<\/p>\n
apt install -y software-properties-common<\/code><\/pre>\n
Configure the feed:<\/p>\n
$ add-apt-repository ppa:dotnet\/backports\r\nPPA publishes dbgsym, you may need to include 'main\/debug' component\r\nRepository: 'Types: deb\r\nURIs: https:\/\/ppa.launchpadcontent.net\/dotnet\/backports\/ubuntu\/\r\nSuites: resolute\r\nComponents: main\r\n'\r\nDescription:\r\nThe backports archive provides source-built .NET packages in cases where a version of .NET is not available in the archive for an Ubuntu release.\r\n\r\nCurrently available Ubuntu releases and .NET backports:\r\n\r\nUbuntu 26.04 LTS (Resolute Raccoon)\r\n\u251c\u2500\u2500 .NET 8.0 (End of Life on November 10th, 2026) [amd64 arm64]\r\n\u2514\u2500\u2500 .NET 9.0 (End of Life on November 10th, 2026) [amd64 arm64 s390x ppc64el]\r\n\r\nUbuntu 24.04 LTS (Noble Numbat)\r\n\u251c\u2500\u2500 .NET 6.0 (End of Life on November 12th, 2024) [amd64 arm64]\r\n\u251c\u2500\u2500 .NET 7.0 (End of Life on May 14th, 2024)      [amd64 arm64]\r\n\u2514\u2500\u2500 .NET 9.0 (End of Life on November 10th, 2026) [amd64 arm64 s390x ppc64el]\r\n\r\nUbuntu 22.04 LTS (Jammy Jellyfish)\r\n\u251c\u2500\u2500 .NET 9.0 (End of Life on November 10th, 2026) [amd64 arm64 s390x ppc64el]\r\n\u2514\u2500\u2500 .NET 10.0 (End of Life on November 14th, 2028) [amd64 arm64 s390x ppc64el]\r\n\r\nCanonical provides best-effort support for packages contained in this archive, which is limited to the upstream lifespan or the support period of the particular Ubuntu version. See the upstream support policy [1] for more information about the upstream support lifespan of .NET releases or the Ubuntu Releases Wiki entry [2] for more information about the support period of any Ubuntu version.\r\n\r\n[1] https:\/\/dotnet.microsoft.com\/en-us\/platform\/support\/policy\/dotnet-core\r\n[2] https:\/\/wiki.ubuntu.com\/Releases\r\nMore info: https:\/\/launchpad.net\/~dotnet\/+archive\/ubuntu\/backports\r\nAdding repository.\r\nPress [ENTER] to continue or Ctrl-c to cancel.<\/code><\/pre>\n
You can see that the support statement for the feed is included.<\/p>\n
Once the feed is registered, new dotnet<\/code> and aspnetcore<\/code> packages will show up. You can filter them by version or see all of them. Whichever you want.<\/p>\n
$ apt list dotnet-*8.0\r\ndotnet-apphost-pack-8.0\/resolute 8.0.26-0ubuntu1~26.04.1~ppa1 amd64\r\ndotnet-host-8.0\/resolute 8.0.26-0ubuntu1~26.04.1~ppa1 amd64\r\ndotnet-hostfxr-8.0\/resolute 8.0.26-0ubuntu1~26.04.1~ppa1 amd64\r\ndotnet-runtime-8.0\/resolute 8.0.26-0ubuntu1~26.04.1~ppa1 amd64\r\ndotnet-runtime-dbg-8.0\/resolute 8.0.26-0ubuntu1~26.04.1~ppa1 amd64\r\ndotnet-sdk-8.0\/resolute 8.0.126-0ubuntu1~26.04.1~ppa1 amd64\r\ndotnet-sdk-dbg-8.0\/resolute 8.0.126-0ubuntu1~26.04.1~ppa1 amd64\r\ndotnet-targeting-pack-8.0\/resolute 8.0.26-0ubuntu1~26.04.1~ppa1 amd64\r\ndotnet-templates-8.0\/resolute 8.0.126-0ubuntu1~26.04.1~ppa1 amd64\r\n$ apt list aspnetcore-runtime-*\r\naspnetcore-runtime-10.0\/resolute 10.0.5-0ubuntu1 amd64\r\naspnetcore-runtime-8.0\/resolute 8.0.26-0ubuntu1~26.04.1~ppa1 amd64\r\naspnetcore-runtime-9.0\/resolute 9.0.15-0ubuntu1~26.04.1~ppa1 amd64\r\naspnetcore-runtime-dbg-10.0\/resolute 10.0.5-0ubuntu1 amd64\r\naspnetcore-runtime-dbg-8.0\/resolute 8.0.26-0ubuntu1~26.04.1~ppa1 amd64\r\naspnetcore-runtime-dbg-9.0\/resolute 9.0.15-0ubuntu1~26.04.1~ppa1 amd64<\/code><\/pre>\n
And the packages that are actually installed on my machine.<\/p>\n
apt list --installed 'aspnetcore*' 'dotnet*'\r\naspnetcore-runtime-10.0\/resolute,now 10.0.5-0ubuntu1 amd64 [installed,automatic]\r\naspnetcore-targeting-pack-10.0\/resolute,now 10.0.5-0ubuntu1 amd64 [installed,automatic]\r\ndotnet-apphost-pack-10.0\/resolute,now 10.0.5-0ubuntu1 amd64 [installed,automatic]\r\ndotnet-host-10.0\/resolute,now 10.0.5-0ubuntu1 amd64 [installed,automatic]\r\ndotnet-hostfxr-10.0\/resolute,now 10.0.5-0ubuntu1 amd64 [installed,automatic]\r\ndotnet-runtime-10.0\/resolute,now 10.0.5-0ubuntu1 amd64 [installed,automatic]\r\ndotnet-sdk-10.0\/resolute,now 10.0.105-0ubuntu1 amd64 [installed,automatic]\r\ndotnet-sdk-aot-10.0\/resolute,now 10.0.105-0ubuntu1 amd64 [installed]\r\ndotnet-targeting-pack-10.0\/resolute,now 10.0.5-0ubuntu1 amd64 [installed,automatic]\r\ndotnet-templates-10.0\/resolute,now 10.0.105-0ubuntu1 amd64 [installed,automatic]<\/code><\/pre>\n
Summary<\/h2>\n
It\u2019s that time again, another Ubuntu LTS. I wrote a similar post two years ago for Ubuntu 24.04<\/a>. Much is the same. This time around, we put in more effort to ensure that preparing for the next Ubuntu LTS was central to the distro versions we chose for CI testing in dotnet\/runtime in the intervening two years. Day-of Ubuntu 26.04 support just \u201cfalls out\u201d of that. Enjoy!<\/p>\n
The post What\u2019s new for .NET in Ubuntu 26.04<\/a> appeared first on .NET Blog<\/a>.<\/p>","protected":false},"excerpt":{"rendered":"
Today is launch day for Ubuntu 26.04 (Resolute Raccoon). Congratulations on the release to our friends at Canonical. Each new […]<\/p>\n","protected":false},"author":1,"featured_media":3913,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[7],"tags":[],"class_list":["post-3912","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-dotnet"],"_links":{"self":[{"href":"https:\/\/rssfeedtelegrambot.bnaya.co.il\/index.php\/wp-json\/wp\/v2\/posts\/3912","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/rssfeedtelegrambot.bnaya.co.il\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/rssfeedtelegrambot.bnaya.co.il\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/rssfeedtelegrambot.bnaya.co.il\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/rssfeedtelegrambot.bnaya.co.il\/index.php\/wp-json\/wp\/v2\/comments?post=3912"}],"version-history":[{"count":0,"href":"https:\/\/rssfeedtelegrambot.bnaya.co.il\/index.php\/wp-json\/wp\/v2\/posts\/3912\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/rssfeedtelegrambot.bnaya.co.il\/index.php\/wp-json\/wp\/v2\/media\/3913"}],"wp:attachment":[{"href":"https:\/\/rssfeedtelegrambot.bnaya.co.il\/index.php\/wp-json\/wp\/v2\/media?parent=3912"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rssfeedtelegrambot.bnaya.co.il\/index.php\/wp-json\/wp\/v2\/categories?post=3912"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rssfeedtelegrambot.bnaya.co.il\/index.php\/wp-json\/wp\/v2\/tags?post=3912"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}