[Lazarus] How to find out why a unit is used in a project?

[John Landmesser]

Am 23.09.20 um 18:59 schrieb Bo Berglund via lazarus:
> I am porting a Delphi application to Linux and as a stop I am first
> doing it from Delphi to Lazarus/Fpc on Windows.
>
> Now when I try to compile it throws an error inside a unit I did not
> even know it used. And to further complicate the issue I cannot find a
> reference to the unit in question when doing a search in the project
> dir inside all pas files. This unit is not mentioned anywhere and
> still causes a compile error due to a missing reference.
>
> I tried Lazarus Find In Files and set it to search "all files in
> project" and also search the project directory, but it comes up
> empty-handed...
>
> So now I wonder:
> Is there a Lazarus tool to trace why the unit is referenced in the
> first place? Is there such things as "chain of uses"?
>
> The application I am porting is a client communications app that talks
> to a service over TCP/IP.
> That service app uses the unit that pos up as erroneous now, but it
> should not be used by the client comm app at all.
> So I need to find out why it does.
>

Perhaps it can be find in Projects properties?