Create optional bill of materials output

[jpobst]

We often get support requests of the form "this works when I build my app on my machine, but fails when I build it on CI". These usually point to a difference in build environments between the machines. Technically, the versions used for all the build tools are probably in a .binlog, but it takes a lot of spelunking and knowledge to be able to compare two .binlog's. Some information is also available in $(IntermediateOutputPath)build.props but it's hidden deep in the obj directory.

If we made this process easier, would it empower users to self-diagnose build environment differences between machines, eliminating the need for our help?

Possible Solution

Nothing is done by default. A user can add the following MSBuild to their project to generate a BOM manifest that is written to the $(OutputPath):

<AndroidGenerateBOMManifest>true</AndroidGenerateBOMManifest>

The file written to the project output can be whatever format but should contain the following non-exhaustive list of information:

• OS Version
• .NET version
• Workload version(s)
• Build Tools version
• Android SDK version
• JDK version
• Cmdline Tools version
• Linker version
• Aapt2 version
• ApkSigner version
• R8 version
• etc.