AppVeyor Octopack - Failing GetAssemblyVersion - asp.net-core

Question

I have a asp.net core 2.0 web app. I am attempting to use AppVeyor to build a nuget package with octopack, so our octopus server can handle our deployment process.
I have the following steps listed in my appveyor.yml file to do the nuget restore, and publish:
before_build:
- cmd: choco install octopustools
- cmd: nuget restore
- cmd: dotnet restore MyApp/MyApp.csproj
- cmd: dotnet publish MyApp/MyApp.csproj --output published-app --configuration=%CONFIGURATION%
- cmd: octo pack --id MyApp --version %APPVEYOR_BUILD_VERSION% --basePath MyApp/published-app
However, when the build reaches the dotnet publish of the site, it fails with the following error:
dotnet publish MyApp/MyApp.csproj --output published-app --configuration=%CONFIGURATION%
Microsoft (R) Build Engine version 15.3.409.57025 for .NET Core
Copyright (C) Microsoft Corporation. All rights reserved.
SendGrid.NetCore -> C:\projects\MyApp\SendGrid.NetCore\bin\Release\netcoreapp2.0\SendGrid.NetCore.dll
MyApp -> C:\projects\MyApp\MyApp\bin\Release\netcoreapp2.0\MyApp.dll
C:\Users\appveyor.nuget\packages\octopack\3.6.3\build\OctoPack.targets(47,5): error MSB4018: The "GetAssemblyVersionInfo" task failed unexpectedly. [C:\projects\MyApp\MyApp\MyApp.csproj]
C:\Users\appveyor.nuget\packages\octopack\3.6.3\build\OctoPack.targets(47,5): error MSB4018: System.IO.FileNotFoundException: Could not load file or assembly 'Microsoft.Build.Utilities.v4.0, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'. The system cannot find the file specified. [C:\projects\MyApp\MyApp\MyApp.csproj]
C:\Users\appveyor.nuget\packages\octopack\3.6.3\build\OctoPack.targets(47,5): error MSB4018: File name: 'Microsoft.Build.Utilities.v4.0, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' [C:\projects\MyApp\MyApp\MyApp.csproj]
C:\Users\appveyor.nuget\packages\octopack\3.6.3\build\OctoPack.targets(47,5): error MSB4018: at OctoPack.Tasks.GetAssemblyVersionInfo.Execute() [C:\projects\MyApp\MyApp\MyApp.csproj]
C:\Users\appveyor.nuget\packages\octopack\3.6.3\build\OctoPack.targets(47,5): error MSB4018: at Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute() [C:\projects\MyApp\MyApp\MyApp.csproj]
C:\Users\appveyor.nuget\packages\octopack\3.6.3\build\OctoPack.targets(47,5): error MSB4018: at Microsoft.Build.BackEnd.TaskBuilder.<ExecuteInstantiatedTask>d__25.MoveNext() [C:\projects\MyApp\MyApp\MyApp.csproj]
C:\Users\appveyor.nuget\packages\octopack\3.6.3\build\OctoPack.targets(47,5): error MSB4018: [C:\projects\MyApp\MyApp\MyApp.csproj]
C:\Users\appveyor.nuget\packages\octopack\3.6.3\build\OctoPack.targets(47,5): error MSB4018: [C:\projects\MyApp\MyApp\MyApp.csproj]
Command exited with code 1
I am unsure why octopack targets would not be found, since I am installing the latest octopustools, and the target should be based upon the referencing project.
UPDATE: I have RDP'd into the build server, and I was able to successfully run the commands from a powershell console, and they were successful. here are the commands, and results of running those commands:
PS C:\projects\MyApp> dotnet publish MyApp/MyApp.csproj --output published-app --configuration=Release
Microsoft (R) Build Engine version 15.3.409.57025 for .NET Core
Copyright (C) Microsoft Corporation. All rights reserved.
SendGrid.NetCore -> C:\projects\MyApp\SendGrid.NetCore\bin\Release\netcoreapp2.0\SendGrid.NetCore.dll
MyApp -> C:\projects\MyApp\MyApp\bin\Release\netcoreapp2.0\MyApp.dll
MyApp -> C:\projects\MyApp\MyApp\published-app\
and here is the octopack step:
PS C:\projects\reportal> octo pack --id Reportal --version 2.2.2.2 --basePath Reportal/published-app
Octopus Deploy Command Line Tool, version 4.27.0
Packing Reportal version "2.2.2.2"...
Saving "Reportal.2.2.2.2.nupkg" to "C:\projects\reportal"...
Done.
*so at this time I am lost why the commands are failing on appveyor runs, but not when I run the same commands when RDP'd into the same machine.
UPDATE #2: I have now realized these commands should have been run as ps (powershell) commands, no standard cmd (bash) commands. I corrected them to
before_build:
- ps: echo buildNumber= $env:appveyor_build_number
- ps: echo configration= $env:configuration
- ps: choco install octopustools
- ps: choco install bower
- ps: nuget restore
- ps: dotnet restore MyApp/MyApp.csproj
- ps: dotnet publish MyApp/MyApp.csproj --output published-app --configuration $env:configuration
- ps: octo pack --id Reportal --version $env:appveyor_build_number --basePath MyApp/published-app
BUT the output still is returning the same error regarding the octopack target shown above. these command are EXACTLY how I am running them from the RDP session, which are building and packaging correctly. So lost on why this auto build fails, but manually running the same commands from the RDP works.

Answer 1

So I got a response from Octopus Deploy that the Octopack nuget package is not been updated to work with .net core projects.
Once I removed the package, the build and package with the octopus tools worked great. here are the full steps that worked for my project:
build_script:
- ps: choco install octopustools --no-progress
- ps: choco install bower --no-progress
- ps: dotnet restore
- ps: dotnet publish MyApp/MyApp.csproj --output published-app --configuration $env:configuration
- ps: octo pack --id MyCompany.MyApp --version $env:appveyor_build_version --basePath MyApp/published-app