Error NU1101 :unable to find package Microsoft.NETCore.App.Host.arch-x64. dotnet 9

[killi1812]

Description

Error when trying to build project with dotnet 9
command: dotnet build

Using launch settings from restService/Properties/launchSettings.json...
Building...
/home/fran/Documents/algebra/iis/restSservice/restService/restService.csproj : error NU1101: Unable to find package Microsoft.NETCore.App.Host.arch-x64. No packages exist with this id in source(s): nuget.org

NuGet log

Start restoring packages for project 'restService'
@ Restoring packages in solution restSservice started
@   RestorePackagesConfig: Start
@   There are no packages in solution
@   RestorePackagesConfig: Finish
@   RestorePackageReferences: Start
@   Restoring NuGet packages for integrated projects: start
@   RestoreEngine = Embedded (Automatic)
@   Valid fallback folders: []
Running restore with 8 concurrent jobs.
Reading project file /home/fran/Documents/algebra/iis/restSservice/restService/restService.csproj.
The restore inputs for 'restService' have changed. Continuing restore.
Restoring packages for /home/fran/Documents/algebra/iis/restSservice/restService/restService.csproj...
  GET https://api.nuget.org/v3-flatcontainer/microsoft.netcore.app.host.arch-x64/index.json
  NotFound https://api.nuget.org/v3-flatcontainer/microsoft.netcore.app.host.arch-x64/index.json 873ms
Unable to find package Microsoft.NETCore.App.Host.arch-x64. No packages exist with this id in source(s): nuget.org
  CACHE https://api.nuget.org/v3/vulnerabilities/index.json
  CACHE https://api.nuget.org/v3-vulnerabilities/2025.05.15.05.31.02/vulnerability.base.json
  CACHE https://api.nuget.org/v3-vulnerabilities/2025.05.15.05.31.02/2025.05.15.05.31.02/vulnerability.update.json
All packages and projects are compatible with net9.0.
Committing restore...
Generating MSBuild file /home/fran/Documents/algebra/iis/restSservice/restService/obj/restService.csproj.nuget.g.props.
Writing assets file to disk. Path: /home/fran/Documents/algebra/iis/restSservice/restService/obj/project.assets.json
Writing cache file to disk. Path: /home/fran/Documents/algebra/iis/restSservice/restService/obj/project.nuget.cache
Persisting dg to /home/fran/Documents/algebra/iis/restSservice/restService/obj/restService.csproj.nuget.dgspec.json
Failed to restore /home/fran/Documents/algebra/iis/restSservice/restService/restService.csproj (in 900 ms).
@   Restoring NuGet packages for integrated projects: finish
@   RestorePackageReferences: Finish
@   Updating restore marks for affected project restService.csproj
@   Updating restore marks for project restService.csproj
@ Restoring packages in solution restSservice finished (0.985 sec)
[Notification][Restore] Restore failed
Restore  in 1 project
Finish restoring packages for project 'restService'

Reproduction Steps

1. Had previously installed dotnet 7
2. Installed dotnet 9 over pacman packet manager
3. Created a new project (console app and web api) with Rider
4. Build project fails

Expected behavior

For project to build
NuGet log for dotnet 8

Start restoring packages for project 'restService'
@ Restoring packages in solution restSservice started
@   RestorePackagesConfig: Start
@   There are no packages in solution
@   RestorePackagesConfig: Finish
@   RestorePackageReferences: Start
@   Restoring NuGet packages for integrated projects: start
@   RestoreEngine = Embedded (Automatic)
@   Valid fallback folders: []
Running restore with 8 concurrent jobs.
Reading project file /home/fran/Documents/algebra/iis/restSservice/restService/restService.csproj.
The restore inputs for 'restService' have changed. Continuing restore.
Restoring packages for /home/fran/Documents/algebra/iis/restSservice/restService/restService.csproj...
  CACHE https://api.nuget.org/v3/vulnerabilities/index.json
  CACHE https://api.nuget.org/v3-vulnerabilities/2025.05.15.05.31.02/vulnerability.base.json
  CACHE https://api.nuget.org/v3-vulnerabilities/2025.05.15.05.31.02/2025.05.15.05.31.02/vulnerability.update.json
All packages and projects are compatible with net8.0.
Committing restore...
Generating MSBuild file /home/fran/Documents/algebra/iis/restSservice/restService/obj/restService.csproj.nuget.g.props.
Writing assets file to disk. Path: /home/fran/Documents/algebra/iis/restSservice/restService/obj/project.assets.json
Writing cache file to disk. Path: /home/fran/Documents/algebra/iis/restSservice/restService/obj/project.nuget.cache
Persisting dg to /home/fran/Documents/algebra/iis/restSservice/restService/obj/restService.csproj.nuget.dgspec.json
Restored /home/fran/Documents/algebra/iis/restSservice/restService/restService.csproj (in 89 ms).
@   Restoring NuGet packages for integrated projects: finish
@   RestorePackageReferences: Finish
@   Updating restore marks for affected project restService.csproj
@   Updating restore marks for project restService.csproj
@   Restore result: Affected projects: restService; Affected packages folders: /home/fran/.nuget/packages
@ Restoring packages in solution restSservice finished (0.102 sec)
Finish restoring packages for project 'restService'

Actual behavior

Tryes to find package Microsoft.NETCore.App.Host.arch-x64 and fails

Regression?

It works normally with dotnet 8 and 7

Known Workarounds

Switch to different version

Configuration

output from dotnet --info

.NET SDK:
 Version:           9.0.105
 Commit:            b7deac6d42
 Workload version:  9.0.100-manifests.3b27a542
 MSBuild version:   17.12.32+b7deac6d4

Runtime Environment:
 OS Name:     manjaro
 OS Version:
 OS Platform: Linux
 RID:         arch-x64
 Base Path:   /usr/share/dotnet/sdk/9.0.105/

.NET workloads installed:
There are no installed workloads to display.
Configured to use loose manifests when installing new manifests.

Host:
  Version:      9.0.4
  Architecture: x64
  Commit:       b7deac6d42

.NET SDKs installed:
  7.0.406 [/usr/share/dotnet/sdk]
  8.0.115 [/usr/share/dotnet/sdk]
  9.0.105 [/usr/share/dotnet/sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.App 7.0.16 [/usr/share/dotnet/shared/Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 8.0.15 [/usr/share/dotnet/shared/Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 9.0.4 [/usr/share/dotnet/shared/Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 6.0.36 [/usr/share/dotnet/shared/Microsoft.NETCore.App]
  Microsoft.NETCore.App 7.0.16 [/usr/share/dotnet/shared/Microsoft.NETCore.App]
  Microsoft.NETCore.App 8.0.15 [/usr/share/dotnet/shared/Microsoft.NETCore.App]
  Microsoft.NETCore.App 9.0.4 [/usr/share/dotnet/shared/Microsoft.NETCore.App]

Other architectures found:
  None

Environment variables:
  Not set

global.json file:
  Not found

Other information

No response

[agocke]

Can you try our official tarball?

[killi1812]

Can you try our official tarball?

• I have tried building it with build.sh but didn't succeed.
• After that I installed dotnet 9.0.5 bin ( runtime, sdk and host) from aur. That worked
• Then i realized that there is dotnet.sh so i used it to build a project and it also worked
• Removing dotnet 9.0.5 bin and installing back 9.0.4 the bug returns. Running it with ./dotnet.sh from official tarball works

Note: I also tried to reproduce this bug on my manjaro desktop but wasn't successful

[agocke]

OK, if this works with the official bits, then the issue should be filed with the package maintainers.

You can also used our official tarballs, the dotnet-install.sh script, or another install tool instead.

If you want a tool for downloading SDKs and keeping them up to date, I have a personal project https://dnvm.net/ that does that, which you could try.