Distzip does not presently work when build output is a directory or multiple files

[dmikusa]

What happened?

The build tools buildpacks based on libbs were recently given the ability to consume multiple build artifacts. They can now specify a folder or multiple files. When this happens, the folder/multiple files are restored to /workspace/<files>, which creates a folder structure under /workspace that dist-zip cannot presently handle. At present, it expects /workspace/bin/* or something like that (exploded dist-zip).

The buildpack should support building from multiple artifacts. It would need to search through /workspace for zip archives, and examine the archive to see if it is a dist-zip archive (i.e. has a */bin/* folder). When found, extract the contents to /workspace and run it.

Checklist

• I have included log output.
• The log output includes an error message.
• I have included steps for reproduction.