.NET 7.0: Arm64 Docker build fails with NullReferenceException for TargetOutputs on restore step

[DrEsteban]

I have a project that I'm trying to upgrade from .NET 6.0 -> .NET 7.0. I run this project as a container on a Raspberry Pi, so I run my docker builds with --platform arm64. I don't build on the Pi, but on my Windows 11 machine.

Here is a direct link to a branch in my project where I'm attempting to upgrade to .NET 7.0: https://github.com/DrEsteban/SolarGateway_PrometheusProxy/tree/net7.0

Repro steps
The following works:

1. Checkout repository
2. Open command prompt to repo root
3. docker build .
4. Produces an image as expected

The following does not work:

1. Checkout repository
2. Open command prompt to repo root
3. docker build --platform arm64 .
4. Fails at the restore step with:

> [build 4/6] RUN dotnet restore "SolarGateway_PrometheusProxy.csproj":
#10 7.132   Determining projects to restore...
#10 7.187 /usr/share/dotnet/sdk/7.0.102/NuGet.targets(1235,7): error MSB4018: The "MSBuild" task failed unexpectedly. [/src/SolarGateway_PrometheusProxy.csproj]
#10 7.187 /usr/share/dotnet/sdk/7.0.102/NuGet.targets(1235,7): error MSB4018: System.NullReferenceException: Object reference not set to an instance of an object. [/src/SolarGateway_PrometheusProxy.csproj]
#10 7.187 /usr/share/dotnet/sdk/7.0.102/NuGet.targets(1235,7): error MSB4018:    at InvokeStub_MSBuild.get_TargetOutputs(Object, Object, IntPtr*) [/src/SolarGateway_PrometheusProxy.csproj]
#10 7.187 /usr/share/dotnet/sdk/7.0.102/NuGet.targets(1235,7): error MSB4018:    at System.Reflection.MethodInvoker.Invoke(Object obj, IntPtr* args, BindingFlags invokeAttr) [/src/SolarGateway_PrometheusProxy.csproj]
#10 7.188 /usr/share/dotnet/sdk/7.0.102/NuGet.targets(1235,7): error MSB4028: The "MSBuild" task's outputs could not be retrieved from the "TargetOutputs" parameter. Object reference not set to an instance of an object. [/src/SolarGateway_PrometheusProxy.csproj]

[alexrosenfeld10]

I'm having the same issue.

[alexrosenfeld10]

seems like a duplicate of #28971 / NuGet/Home#12227?

[DrEsteban]

@alexrosenfeld10 The root cause could very well be the same, but note the error messages in those 2 issues are much different than what I'm seeing. Same step in the process, but a very different error.

[DrEsteban]

Also, here's an update. I just pulled the latest versions of mcr.microsoft.com/dotnet/sdk:7.0 and mcr.microsoft.com/dotnet/aspnet:7.0 and tried the build again, and the error message is slightly different now:

 > [build 4/6] RUN dotnet restore "SolarGateway_PrometheusProxy.csproj":
#11 8.090   Determining projects to restore...
#11 8.256 /usr/share/dotnet/sdk/7.0.103/NuGet.targets(1109,7): error MSB4018: The "RemoveDuplicates" task failed unexpectedly. [/src/SolarGateway_PrometheusProxy.csproj]
#11 8.256 /usr/share/dotnet/sdk/7.0.103/NuGet.targets(1109,7): error MSB4018: System.NullReferenceException: Object reference not set to an instance of an object. [/src/SolarGateway_PrometheusProxy.csproj]
#11 8.256 /usr/share/dotnet/sdk/7.0.103/NuGet.targets(1109,7): error MSB4018:    at InvokeStub_RemoveDuplicates.get_Filtered(Object, Object, IntPtr*) [/src/SolarGateway_PrometheusProxy.csproj]
#11 8.256 /usr/share/dotnet/sdk/7.0.103/NuGet.targets(1109,7): error MSB4018:    at System.Reflection.MethodInvoker.Invoke(Object obj, IntPtr* args, BindingFlags invokeAttr) [/src/SolarGateway_PrometheusProxy.csproj]
#11 8.257 /usr/share/dotnet/sdk/7.0.103/NuGet.targets(1109,7): error MSB4028: The "RemoveDuplicates" task's outputs could not be retrieved from the "Filtered" parameter. Object reference not set to an instance of an object. [/src/SolarGateway_PrometheusProxy.csproj]

[DrEsteban]

And just to clarify, this issue doesn't repro at all when I use the .NET 6 SDK & images.

[alexrosenfeld10]

yep I downgraded to net6.0 today because of similar stuff.

[marcpopMSFT]

Adding @richlander who's been doing a lot of docker scenarios similar to this one to take a look.

[austinlparker]

Also seeing this intermittently when running .NET 7 builds in QEMU. Logs here: https://gist.github.com/austinlparker/b512198a748f67cf6574b684f2648c52

[Jesn]

#50 29.03 /usr/share/dotnet/sdk/7.0.400/NuGet.targets(1244,7): error MSB4018:    at System.Reflection.MethodInvoker.Invoke(Object obj, IntPtr* args, BindingFlags invokeAttr) [**/HttpApi.Host.csproj]

#50 29.03 /usr/share/dotnet/sdk/7.0.400/NuGet.targets(1244,7): error MSB4028: The "MSBuild" task's outputs could not be retrieved from the "TargetOutputs" parameter. Object reference not set to an instance of an object. [**/Rich.MagicNetWork.HttpApi.Host.csproj]

I have also encountered similar problems. I have succeeded several times, but 99% have failed

[Jesn]

FROM --platform=$BUILDPLATFORM mcr.microsoft.com/dotnet/sdk:7.0 AS build

add --platform=$BUILDPLATFORM

[werwolfby]

@Jesn thanks! --platform=$BUILDPLATFORM really helped!

[DrEsteban]

Hmm I tried adding the --platform flag to the Dockerfile itself as described above, but continue to see the same issues during package restore.

[DrEsteban]

This article, and .NET 8.0 in general, has helped me greatly!!

https://devblogs.microsoft.com/dotnet/improving-multiplatform-container-support/

[DrEsteban]

Marking as closed due to improvements in .NET 8.0 container support.

[yabood]

FROM --platform=$BUILDPLATFORM mcr.microsoft.com/dotnet/sdk:7.0 AS build

add --platform=$BUILDPLATFORM

This worked, thanks!