Razor error when building Blazor Client app on MS SDK docker container

[dazinator]

Describe the bug

UPDATE: Please see comment below for Docker.develop file that I had missed from this original post.

I have a blazor client project & asp.net core server project in my solution.
I thought i'd have a go at deploying it to an AKS cluster using visual studio "dev spaces"
This basically adds a DOCKER file to project which copies your source code into a build container and does the build of the solution inside that container.

Here is the DOCKERFILE that was generated for me:

FROM mcr.microsoft.com/dotnet/core/aspnet:3.0 AS base
WORKDIR /app
EXPOSE 80

FROM mcr.microsoft.com/dotnet/core/sdk:3.0 AS build
WORKDIR /src
COPY ["Hub.Platform.Client/Hub.Platform.Client.csproj", "Hub.Platform.Client/"]
COPY ["Hub.Platform.Core/Hub.Platform.Core.csproj", "Hub.Platform.Core/"]
COPY ["Hub.Platform.Server/Hub.Platform.Server.csproj", "Hub.Platform.Server/"]
COPY ["Hub.Platform.Shared/Hub.Platform.Shared.csproj", "Hub.Platform.Shared/"]

RUN dotnet restore "Hub.Platform.Server/Hub.Platform.Server.csproj"
COPY . .
WORKDIR "/src/Hub.Platform.Server"
RUN dotnet build "Hub.Platform.Server.csproj" -c Release -o /app

FROM build AS publish
RUN dotnet publish "Hub.Platform.Server.csproj" -c Release -o /app

FROM base AS final
WORKDIR /app
COPY --from=publish /app .
ENTRYPOINT ["dotnet", "Hub.Platform.Server.dll"]

When this runs, the build fails at the following step with this output:

Step 14/16 : RUN dotnet build --no-restore "Hub.Platform.Server.csproj" -c $BUILD_CONFIGURATION
---> Running in 5db3c6447be5
Microsoft (R) Build Engine version 16.0.462+g62fb89029d for .NET Core
Copyright (C) Microsoft Corporation. All rights reserved.
/usr/share/dotnet/sdk/3.0.100-preview5-011568/Sdks/Microsoft.NET.Sdk/targets/Microsoft.NET.RuntimeIdentifierInference.targets(157,5): message NETSDK1057: You are using a preview version of .NET Core. See: https://aka.ms/dotnet-core-preview [/src/Hub.Platform.Server/Hub.Platform.Server.csproj]
/usr/share/dotnet/sdk/3.0.100-preview5-011568/Sdks/Microsoft.NET.Sdk/targets/Microsoft.NET.RuntimeIdentifierInference.targets(157,5): message NETSDK1057: You are using a preview version of .NET Core. See: https://aka.ms/dotnet-core-preview [/src/Hub.Platform.Core/Hub.Platform.Core.csproj]
Hub.Platform.Shared -> /src/Hub.Platform.Shared/bin/Debug/netstandard2.0/Hub.Platform.Shared.dll
WritableOptions/WritableOptions.cs(13,26): warning CS0618: 'IHostingEnvironment' is obsolete: 'This type is obsolete and will be removed in a future version. The recommended alternative is Microsoft.Extensions.Hosting.IHostEnvironment.' [/src/Hub.Platform.Core/Hub.Platform.Core.csproj]
WritableOptions/WritableOptions.cs(20,13): warning CS0618: 'IHostingEnvironment' is obsolete: 'This type is obsolete and will be removed in a future version. The recommended alternative is Microsoft.Extensions.Hosting.IHostEnvironment.' [/src/Hub.Platform.Core/Hub.Platform.Core.csproj]
WritableOptions/ServiceCollectionExtensions.cs(19,55): warning CS0618: 'IHostingEnvironment' is obsolete: 'This type is obsolete and will be removed in a future version. The recommended alternative is Microsoft.Extensions.Hosting.IHostEnvironment.' [/src/Hub.Platform.Core/Hub.Platform.Core.csproj]
Pages/Index.razor(43,24): warning CS1998: This async method lacks 'await' operators and will run synchronously. Consider using the 'await' operator to await non-blocking API calls, or 'await Task.Run(...)' to do CPU-bound work on a background thread. [/src/Hub.Platform.Client/Hub.Platform.Client.csproj]
Pages/Index.razor(43,24): warning CS1998: This async method lacks 'await' operators and will run synchronously. Consider using the 'await' operator to await non-blocking API calls, or 'await Task.Run(...)' to do CPU-bound work on a background thread. [/src/Hub.Platform.Client/Hub.Platform.Client.csproj]
Hub.Platform.Client -> /src/Hub.Platform.Client/bin/Debug/netstandard2.0/Hub.Platform.Client.dll
Processing embedded resource linker descriptor: mscorlib.xml
Duplicate preserve in resource mscorlib.xml in mscorlib, Version=2.0.5.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e of System.Threading.WasmRuntime (All). Duplicate uses (All)
Type System.Reflection.Assembly has no fields to preserve
Type Mono.ValueTuple has no fields to preserve
Output action: Link assembly: Hub.Platform.Client, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null
Output action: Save assembly: Hub.Platform.Shared, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null
Output action: Save assembly: System.ComponentModel.Annotations, Version=4.2.2.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
Output action: Save assembly: Mono.WebAssembly.Interop, Version=3.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60
Output action: Save assembly: Microsoft.JSInterop, Version=3.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60
Output action: Save assembly: Microsoft.Extensions.DependencyInjection.Abstractions, Version=3.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60
Output action: Save assembly: Microsoft.Extensions.DependencyInjection, Version=3.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60
Output action: Save assembly: Microsoft.AspNetCore.Components.Browser, Version=3.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60
Output action: Save assembly: Microsoft.AspNetCore.Components, Version=3.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60
Output action: Save assembly: Microsoft.AspNetCore.Blazor, Version=3.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60
Output action: Delete assembly: netstandard, Version=2.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51
Output action: Link assembly: mscorlib, Version=2.0.5.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e
Output action: Link assembly: System, Version=2.0.5.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e
Output action: Link assembly: Mono.Security, Version=2.0.5.0, Culture=neutral, PublicKeyToken=0738eb9f132ed756
Output action: Delete assembly: System.Xml, Version=2.0.5.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e
Output action: Delete assembly: System.Numerics, Version=2.0.5.0, Culture=neutral, PublicKeyToken=b77a5c561934e089
Output action: Link assembly: System.Core, Version=2.0.5.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e
Output action: Link assembly: System.Data, Version=2.0.5.0, Culture=neutral, PublicKeyToken=b77a5c561934e089
Output action: Delete assembly: System.Drawing.Common, Version=4.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51
Output action: Delete assembly: System.IO.Compression, Version=2.0.5.0, Culture=neutral, PublicKeyToken=b77a5c561934e089
Output action: Delete assembly: System.IO.Compression.FileSystem, Version=2.0.5.0, Culture=neutral, PublicKeyToken=b77a5c561934e089
Output action: Delete assembly: System.ComponentModel.Composition, Version=2.0.5.0, Culture=neutral, PublicKeyToken=b77a5c561934e089
Output action: Link assembly: System.Net.Http, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
Output action: Delete assembly: System.Runtime.Serialization, Version=2.0.5.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e
Output action: Delete assembly: System.Transactions, Version=2.0.5.0, Culture=neutral, PublicKeyToken=b77a5c561934e089
Output action: Delete assembly: System.Web.Services, Version=2.0.5.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
Output action: Delete assembly: System.Xml.Linq, Version=2.0.5.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35
Output action: Delete assembly: System.ServiceModel.Internals, Version=0.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35
Writing boot data to: /src/Hub.Platform.Client/obj/Debug/netstandard2.0/blazor/blazor.boot.json
Blazor Build result -> 23 files in /src/Hub.Platform.Client/bin/Debug/netstandard2.0/dist
It was not possible to find any compatible framework version
The specified framework 'Microsoft.NETCore.App', version '2.0.9' was not found.

• The following frameworks were found:
  3.0.0-preview5-27626-15 at [/usr/share/dotnet/shared/Microsoft.NETCore.App]
  You can resolve the problem by installing the specified framework and/or SDK.
  The .NET Core frameworks can be found at:
• https://aka.ms/dotnet-download
  /root/.nuget/packages/microsoft.aspnetcore.razor.design/2.2.0/build/netstandard2.0/Microsoft.AspNetCore.Razor.Design.CodeGeneration.targets(79,5): error : rzc discover exited with code 150. [/src/Hub.Platform.Core/Hub.Platform.Core.csproj]
  Build FAILED.

Note, the razor error.
The DOCKERFILE was generated for me by Azure Dev Spaces functionality within Visual Studio. Do I need to be using different base docker images in order to build a blazor application?

To Reproduce

Steps to reproduce the behavior:

1. Create a new Blazor client app hosted by an asp.net core web site project, using latest VS2019 preview.
2. Follow this getting started to use Dev Spaces and deploy the solution to an AKS cluster: https://docs.microsoft.com/en-us/azure/dev-spaces/quickstart-netcore-visualstudio
3. The exception occurs during the docker container build step.

Expected behavior

Build should succeed.

Additional context

Add any other context about the problem here.
Include the output of dotnet --info

dotnet --info
.NET Core SDK (reflecting any global.json):
Version: 3.0.100-preview5-011568
Commit: b487ff10aa

Runtime Environment:
OS Name: Windows
OS Version: 10.0.17134
OS Platform: Windows
RID: win10-x64
Base Path: C:\Program Files\dotnet\sdk\3.0.100-preview5-011568\

Host (useful for support):
Version: 3.0.0-preview5-27626-15
Commit: 61f30f5a23

.NET Core SDKs installed:
1.1.13 [C:\Program Files\dotnet\sdk]
2.1.502 [C:\Program Files\dotnet\sdk]
2.1.503 [C:\Program Files\dotnet\sdk]
2.1.504 [C:\Program Files\dotnet\sdk]
2.1.505 [C:\Program Files\dotnet\sdk]
2.1.507 [C:\Program Files\dotnet\sdk]
2.1.600 [C:\Program Files\dotnet\sdk]
2.1.602 [C:\Program Files\dotnet\sdk]
2.1.700-preview-009601 [C:\Program Files\dotnet\sdk]
2.1.700-preview-009618 [C:\Program Files\dotnet\sdk]
2.1.800-preview-009677 [C:\Program Files\dotnet\sdk]
2.2.101 [C:\Program Files\dotnet\sdk]
3.0.100-preview5-011568 [C:\Program Files\dotnet\sdk]

.NET Core runtimes installed:
Microsoft.AspNetCore.All 2.1.6 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.All 2.1.7 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.All 2.1.8 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.All 2.1.9 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.All 2.1.11 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.All 2.2.0 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.App 2.1.6 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 2.1.7 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 2.1.8 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 2.1.9 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 2.1.11 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 2.2.0 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 3.0.0-preview5-19227-01 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.NETCore.App 1.0.15 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 1.1.12 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 2.1.6 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 2.1.7 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 2.1.8 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 2.1.9 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 2.1.11 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 2.2.0 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 3.0.0-preview5-27626-15 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.WindowsDesktop.App 3.0.0-preview5-27626-15 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

[dazinator]

Sorry I forgot to also include the DockerFile.develop which it seems is actually the one that is run and contains the build instruction that fails:

FROM mcr.microsoft.com/dotnet/core/sdk:3.0
ARG BUILD_CONFIGURATION=Debug
ENV ASPNETCORE_ENVIRONMENT=Development
ENV DOTNET_USE_POLLING_FILE_WATCHER=true
EXPOSE 80

WORKDIR /src
COPY ["Hub.Platform.Client/Hub.Platform.Client.csproj", "Hub.Platform.Client/"]
COPY ["Hub.Platform.Core/Hub.Platform.Core.csproj", "Hub.Platform.Core/"]
COPY ["Hub.Platform.Server/Hub.Platform.Server.csproj", "Hub.Platform.Server/"]
COPY ["Hub.Platform.Shared/Hub.Platform.Shared.csproj", "Hub.Platform.Shared/"]

RUN dotnet restore "Hub.Platform.Server/Hub.Platform.Server.csproj"
COPY . .
WORKDIR "/src/Hub.Platform.Server"
RUN dotnet build --no-restore "Hub.Platform.Server.csproj" -c $BUILD_CONFIGURATION

RUN echo "exec dotnet run --no-build --no-launch-profile -c $BUILD_CONFIGURATION --" > /entrypoint.sh

ENTRYPOINT ["/bin/bash", "/entrypoint.sh"]

[dazinator]

It looks to me that this issue is because the blazor client csproj (which targets netstandard2.0 so that it can run in mono in the browser) ends up invoking this target:

/root/.nuget/packages/microsoft.aspnetcore.razor.design/2.2.0/build/netstandard2.0/Microsoft.AspNetCore.Razor.Design.CodeGeneration.targets(79,5):

and that seems to rely on 'Microsoft.NETCore.App', version '2.0.9' to do it's stuff, but the dotnet sdk 2.0 isn't installed on the mcr.microsoft.com/dotnet/core/sdk:3.0 docker image under which we are building the host website project that references the client blazor project in order to serve it up. Not sure how best to resolve. I guess the easiest thing to do what be to also install the .net sdk 2.0 into the build image. If anyone can share a RUN command to do that would be useful

[dazinator]

I have tried to install dotnet sdk into my docker image derived from the base image mcr.microsoft.com/dotnet/core/sdk:3. to correct this issue but I can't figure out how to install it. It's a debian10 based image and there are no instructions for installing dotnet core sdk into debian 10. The debian9 instructions here didn't work: https://dotnet.microsoft.com/download/linux-package-manager/rhel/sdk-2.1.700

I have opened a related issue for that here: dotnet/core#2830

[rynowak]

Razor.Design 2.2 shouldn't be involved with a Blazor app anymore... I'll look into this, thanks for digging in to find more details.

[rynowak]

@dazinator - do you have Razor.Design listed in the .csproj?

[dazinator]

Nope. Here is my Blazor client csproj:

<Project Sdk="Microsoft.NET.Sdk.Web">

  <PropertyGroup>
    <TargetFramework>netstandard2.0</TargetFramework>
    <OutputType>Exe</OutputType>
    <RestoreAdditionalProjectSources>
      https://dotnet.myget.org/F/aspnetcore-dev/api/v3/index.json;
      https://dotnet.myget.org/F/blazor-dev/api/v3/index.json;
    </RestoreAdditionalProjectSources>
    <LangVersion>7.3</LangVersion>
    <RazorLangVersion>3.0</RazorLangVersion>
  
  </PropertyGroup>

  <ItemGroup>
    
    <PackageReference Include="Microsoft.AspNetCore.Blazor" Version="3.0.0-preview5-19227-01" />
    <PackageReference Include="Microsoft.AspNetCore.Blazor.Build" Version="3.0.0-preview5-19227-01" PrivateAssets="all" />
  </ItemGroup>

  <ItemGroup>
    <ProjectReference Include="..\Hub.Platform.Shared\Hub.Platform.Shared.csproj" />
  </ItemGroup>

</Project>

By the way I spent all day on this and managed to get the build to suceed by installing dotnet core sdk 2.1 into the sdk 3.0 docker image. Which wasn't a straightforward process. Here is a docker file with the ammendments necessary to complete a build:

FROM mcr.microsoft.com/dotnet/core/sdk:3.0
ARG BUILD_CONFIGURATION=Debug
ENV ASPNETCORE_ENVIRONMENT=Development
ENV DOTNET_USE_POLLING_FILE_WATCHER=true
EXPOSE 80

WORKDIR /src

# Issue 1. sudo is not present on this debian 10 based image. Need sudo for other steps in the resolution.
RUN apt-get update && apt-get install -y sudo

# Issue 2. apt-get install fails for dot net packages, becuase we need to add the microsoft package sources to the apt-get sources lists.
RUN wget -qO- https://packages.microsoft.com/keys/microsoft.asc | gpg --dearmor > microsoft.asc.gpg
RUN sudo mv microsoft.asc.gpg /etc/apt/trusted.gpg.d/
RUN sudo chown root:root /etc/apt/trusted.gpg.d/microsoft.asc.gpg

RUN wget -q https://packages.microsoft.com/config/debian/9/prod.list
RUN sudo mv prod.list /etc/apt/sources.list.d/microsoft-prod.list
RUN sudo chown root:root /etc/apt/sources.list.d/microsoft-prod.list

# Not sure what this does but I think its necessary after modifying the sources lists..
RUN sudo apt-get update

# apt-get install still fails for dotnet sdk 2.1 as it says there are missing libraries. Must install these manually.
RUN wget http://debian.mirrors.uk2.net/pool/main/i/icu/libicu57_57.1-6+deb9u2_amd64.deb
RUN wget http://debian.mirrors.uk2.net/pool/main/o/openssl1.0/libssl1.0.2_1.0.2r-1~deb9u1_amd64.deb

RUN dpkg -i libicu57*.deb
RUN dpkg -i libssl1.0.2*.deb

# Now we can install dotnet sdk 2.1...
RUN sudo apt-get install -y dotnet-sdk-2.1

# Finally we can build a blazor server project that references a blazor client project.
COPY ["Hub.Platform.Client/Hub.Platform.Client.csproj", "Hub.Platform.Client/"]
COPY ["Hub.Platform.Core/Hub.Platform.Core.csproj", "Hub.Platform.Core/"]
COPY ["Hub.Platform.Server/Hub.Platform.Server.csproj", "Hub.Platform.Server/"]
COPY ["Hub.Platform.Shared/Hub.Platform.Shared.csproj", "Hub.Platform.Shared/"]
RUN dotnet new -i Microsoft.AspNetCore.Blazor.Templates::3.0.0-preview5-19227-01
RUN dotnet restore "Hub.Platform.Server/Hub.Platform.Server.csproj"
COPY . .
WORKDIR "/src/Hub.Platform.Server"
RUN dotnet build --no-restore "Hub.Platform.Server.csproj" -c $BUILD_CONFIGURATION

RUN echo "exec dotnet run --no-build --no-launch-profile -c $BUILD_CONFIGURATION --" > /entrypoint.sh

ENTRYPOINT ["/bin/bash", "/entrypoint.sh"]

[rynowak]

@pranavkm - do you have any idea why Razor.Design would be getting pulled in? This seems really bizzare.

[dazinator]

Ah ok so..

Perhaps its this...

My solution structure looks like this:

Hub.Platform.Client references Hub.Platform.Shared
Hub.Platform.Server references Hub.Platform.Shared
Hub.Platform.Server references Hub.Platform.Core
Hub.Platform.Server references Hub.Platform.Client

Hub.Platform.Core.csproj is probably the culprit - it's csproj looks like this:

<Project Sdk="Microsoft.NET.Sdk.Razor">

  <PropertyGroup>
    <TargetFramework>netstandard2.1</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <None Remove="Views\Platform\site.css" />
  </ItemGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.AspNetCore.Http.Abstractions" Version="2.2.0" />
    <PackageReference Include="Microsoft.Extensions.Hosting.Abstractions" Version="3.0.0-preview5.19227.9" />
    <PackageReference Include="Microsoft.Extensions.Options" Version="3.0.0-preview5.19227.9" />
    <PackageReference Include="Microsoft.Extensions.Options.ConfigurationExtensions" Version="3.0.0-preview5.19227.9" />
    <PackageReference Include="Newtonsoft.Json" Version="12.0.2" />
    <PackageReference Include="Microsoft.AspNetCore.Mvc" Version="2.2.0" />
  </ItemGroup>

  <ItemGroup>
    <Folder Include="Views\Shared\" />
  </ItemGroup>

</Project>

It's a razor class library and it's using mvc 2.x doh!

Sorry that's slightly embarrassing. Still I guess there are going to be reusable razor view nuget packages out there that were compiled targeting asp.net 2.X that will be referenced from 3.X mvc applications - i.e so do we actually care about this use case? In my view, the sdk 3 docker image should be able to build projects that indirectly pull in 2.x references ?

[kdcllc]

The following project builds inside VS.NET on a windows box with the version of AspNetCore=Version: 3.0.0-preview8-28405-07

<Project Sdk="Microsoft.NET.Sdk.Razor">

  <PropertyGroup>
    <TargetFramework>netstandard2.0</TargetFramework>
    <GenerateEmbeddedFilesManifest>True</GenerateEmbeddedFilesManifest>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.AspNetCore.Mvc" />
    <PackageReference Include="Microsoft.AspNetCore.StaticFiles" />
    <PackageReference Include="Microsoft.Extensions.FileProviders.Embedded" />
  </ItemGroup>

  <ItemGroup>
    <EmbeddedResource Include="wwwroot\**\*" />
    <Content Update="**\*.cshtml" Pack="false" />
  </ItemGroup>
</Project>

In the docker container it fails.

Ended up installing DotNetCore 2.2 into docker container as follows:

FROM mcr.microsoft.com/dotnet/core/sdk:3.0.100-preview8-buster AS build

# Install .NET Core SDK
# https://github.com/aspnet/AspNetCore/issues/10833#issuecomment-499134467
ENV DOTNET_SDK_VERSION 2.2.401

RUN curl -SL --output dotnet.tar.gz https://dotnetcli.blob.core.windows.net/dotnet/Sdk/$DOTNET_SDK_VERSION/dotnet-sdk-$DOTNET_SDK_VERSION-linux-x64.tar.gz \
    && dotnet_sha512='08e1fcafa4f898c80ff5e88eeb40c7497b4f5651af3b8ec85f65a3daa2f1509a766d833477358d3ff83d179e014034ab0c48120847ef24736c8d1a5b67fec10b' \
    && echo "$dotnet_sha512 dotnet.tar.gz" | sha512sum -c - \
    && tar -zxf dotnet.tar.gz -C /usr/share/dotnet \
    && rm dotnet.tar.gz

[pranavkm]

Hi, it looks like you are posting on a closed issue/PR/commit!

We're very likely to lose track of your bug/feedback/question unless you:

1. Open a new issue
2. Explain very clearly what you need help with
3. If you think you have found a bug, include detailed repro steps so that we can investigate the problem

Thanks!