MSB3539 when redirecting build output in web project

[urbanhop]

A most common task when configuring a build is to specify the output path. This task must be really easy and hasslefree.

Currently it is not possible to redirect the path for a web project without receiving a warning. Using the following directory.build.properties

<PropertyGroup>
  <OutputPath>../acmebin</OutputPath>
  <BaseIntermediateOutputPath>../acmebin/obj</BaseIntermediateOutputPath>
  <MSBuildProjectExtensionsPath>../acmebin/obj/$(MSBuildProjectName)</MSBuildProjectExtensionsPath>
  <RestoreOutputPath>../acmebin/obj/$(MSBuildProjectName)</RestoreOutputPath>
</PropertyGroup>

gives the warning

C:\Program Files (x86)\Microsoft Visual Studio\2019\Preview\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets(813,5): warning MSB3539: The value of the property "BaseIntermediateOutputPath" was modified after it was used by MSBuild which can lead to unexpected build results. ...

Expected behavior is no warning. Alternatively any simple way to configure the output directory would be ok.

[livarcocc]

@dsplaisted can you direct to appropriate docs/answer for this?

[urbanhop]

@livarcocc Is there any (correct) documentation about BaseIntermediateOutputPath at all? See this question: https://stackoverflow.com/questions/45096549/where-is-full-documentation-about-the-csproj-format-for-net-core

When searching for documentation I just find people struggling with setting the output path of a build - again the most rudimentary aspect one would want to configure. For instance in https://stackoverflow.com/questions/45750068/setting-of-baseintermediateoutputpath-prevents-running-targets-from-nuget Martin Ulrich comments:

"Note that a Directory.Build.props file would be imported early enough in the common props to correctly set BaseIntermediateOutputPath. – Martin Ullrich"

While that works for some projects, it does not work clean for AspNet core applications, where setting the BaseIntermediateOutputPath in Directory.Build.Props raises the warning mentioned in my first post above. So in other words the problem raised here is:

How can I change the build output directory of an AspNet core application? Setting it in build.props works but gives a warning whose meaning remains unknown.

[dsplaisted]

We want to make this a lot simpler. Here is the issue tracking that: #3497

In that issue or in other issues it links to you can find examples of how people are doing this today.

Thanks!