build runner cannot handle packages in dependency cache with unincluded files #2573
Description
The paths field in the build.zig.zon species which files and directories are included in a package. Any files that are not included will be missing when a package has been fetched with zig fetch into the global zig cache.
This means that ZLS cannot traverse and analyze the entire build graph because some of the existing build steps may depend on non included files. I am unaware of any reliable way to know which steps are safe to analyze. The steps in top level install step are often fine but not even that has to be the case.
Without this knowledge, the build runner has no way to filter out error message that are caused by unincluded files as opposed to genuine errors that should be forwarded to the user.