PublishSingleFile=true and PackAsTool=true in csproj do not play well with dotnet pack

Steps to reproduce

• dotnet new console -n test -o .
• Add <PackAsTool>true</PackAsTool> and <PublishSingleFile>true</PublishSingleFile> to test.csproj
• dotnet pack

Expected behavior

As I understand it, .NET Core tool packages are RID-agnostic, so PublishSingleFile should be ignored by dotnet pack and only be observed by dotnet publish. I am not sure what the behavior should be for PackAsTool=false.

Actual behavior

$ dotnet publish -r linux-x64 # Works as expected.
Microsoft (R) Build Engine version 16.3.0-preview-19329-01+d31fdbf01 for .NET Core
Copyright (C) Microsoft Corporation. All rights reserved.

  Restore completed in 77.09 ms for /home/alexrp/tests/netcore/test.csproj.
  You are using a preview version of .NET Core. See: https://aka.ms/dotnet-core-preview
  test -> /home/alexrp/tests/netcore/bin/Debug/netcoreapp3.0/linux-x64/test.dll
  test -> /home/alexrp/tests/netcore/bin/Debug/netcoreapp3.0/linux-x64/publish/
$ ls bin/Debug/netcoreapp3.0/linux-x64/publish
test  test.pdb
$ dotnet pack # Fails unexpectedly.
Microsoft (R) Build Engine version 16.3.0-preview-19329-01+d31fdbf01 for .NET Core
Copyright (C) Microsoft Corporation. All rights reserved.

  Restore completed in 57.33 ms for /home/alexrp/tests/netcore/test.csproj.
/home/alexrp/.dotnet/sdk/3.0.100-preview7-012821/Sdks/Microsoft.NET.Sdk/targets/Microsoft.NET.RuntimeIdentifierInference.targets(134,5): error NETSDK1097: It is not supported to publish an application to a single-file without specifying a RuntimeIdentifier. Please either specify a RuntimeIdentifier or set PublishSingleFile to false. [/home/alexrp/tests/netcore/test.csproj]

(Incidentally, passing --runtime linux-x64 to dotnet pack makes no difference.)

Environment data

$ dotnet --info
.NET Core SDK (reflecting any global.json):
 Version:   3.0.100-preview7-012821
 Commit:    6348f1068a

Runtime Environment:
 OS Name:     ubuntu
 OS Version:  18.10
 OS Platform: Linux
 RID:         ubuntu.18.10-x64
 Base Path:   /home/alexrp/.dotnet/sdk/3.0.100-preview7-012821/

Host (useful for support):
  Version: 3.0.0-preview7-27912-14
  Commit:  4da6ee6450

.NET Core SDKs installed:
  2.1.604 [/home/alexrp/.dotnet/sdk]
  2.2.204 [/home/alexrp/.dotnet/sdk]
  3.0.100-preview6-012264 [/home/alexrp/.dotnet/sdk]
  3.0.100-preview7-012821 [/home/alexrp/.dotnet/sdk]

.NET Core runtimes installed:
  Microsoft.AspNetCore.All 2.1.11 [/home/alexrp/.dotnet/shared/Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.All 2.2.5 [/home/alexrp/.dotnet/shared/Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.App 2.1.11 [/home/alexrp/.dotnet/shared/Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 2.2.5 [/home/alexrp/.dotnet/shared/Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 3.0.0-preview6.19307.2 [/home/alexrp/.dotnet/shared/Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 3.0.0-preview7.19365.7 [/home/alexrp/.dotnet/shared/Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 2.1.11 [/home/alexrp/.dotnet/shared/Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.2.5 [/home/alexrp/.dotnet/shared/Microsoft.NETCore.App]
  Microsoft.NETCore.App 3.0.0-preview6-27804-01 [/home/alexrp/.dotnet/shared/Microsoft.NETCore.App]
  Microsoft.NETCore.App 3.0.0-preview7-27912-14 [/home/alexrp/.dotnet/shared/Microsoft.NETCore.App]

To install additional .NET Core runtimes or SDKs:
  https://aka.ms/dotnet-download

[alexrp]

Well, I’m not saying they should necessarily be silently ignored. A simple warning would suffice, I’d think. There’s precedent for that too with e.g. the ApplicationIcon property:

$ dotnet publish win-x64
Microsoft (R) Build Engine version 16.3.0-preview-19329-01+d31fdbf01 for .NET Core
Copyright (C) Microsoft Corporation. All rights reserved.

  Restore completed in 111.73 ms for /home/alexrp/flare/flare/src/cli/cli.csproj.
  Restore completed in 111.74 ms for /home/alexrp/flare/flare/src/lib/lib.csproj.
  You are using a preview version of .NET Core. See: https://aka.ms/dotnet-core-preview
  lib -> /home/alexrp/flare/flare/src/lib/bin/Debug/libflare.dll
/home/alexrp/.dotnet/sdk/3.0.100-preview7-012821/Sdks/Microsoft.NET.Sdk/targets/Microsoft.NET.Sdk.targets(358,5): warning NETSDK1074: The application host executable will not be customized because adding resources requires that the build be performed on Windows (excluding Nano Server). [/home/alexrp/flare/flare/src/cli/cli.csproj]
  cli -> /home/alexrp/flare/flare/src/cli/bin/Debug/win-x64/flare.dll
  cli -> /home/alexrp/flare/flare/src/cli/bin/Debug/win-x64/publish/

Alternatively, if there was a way to set these properties in the project file based on which publish command is being executed, that would be fine too.

[alexrp]

In any case, I would have to say that, for me, the most surprising behavior here is the fact that these properties (whose names start with Publish) are being observed by the dotnet pack command at all. From my perspective as a user, packing and publishing have nothing whatsoever to do with each other. This is further backed up by the existence of the distinct IsPackable and IsPublishable properties. It may be the case that they share some MSBuild logic under the hood, but I don’t think that’s obvious to a user at all unless they go digging through the MSBuild files and/or try these properties and discover that they apply to dotnet pack for some reason.