No Project Recurse option should exclude alire directory

[pjljvandelaar]

When analyzing the top project only (using the --no-project-recurse flag)
of an alire project, we should also filter the alire directory that contains all dependencies (needed projects).

[pjljvandelaar]

First of all, what is meant with recursive analysis?

When a project is referenced, what should be analyzed from this project?
A. For projects whose source code is available, real recursive analysis is possible - but is it wanted?
B. For projects where only the interface (*.ads file) are available, analysis can't continue any further - but is it needed?

With Alire, all projects fall in the A. category.

Second,

1. The no-project-recurse flag is not documented at https://github.com/TNO/Dependency_Graph_Extractor-Ada/blob/main/README.md.
   So is it a

• feature for the user
• developer options

2. The user can specify a non-empty list of projects to analyse. However, nothing is specified about the presence/absence of relations between these projects. I.e. is a project and a dependent project thereof allowed together? And if so, is there a difference with only that project [when the --no-project-recurse-flag is absent]?
   This causes that there are (at least) two options to filter relations between projects.
   A. Using the arguments of dependency_graph_extractor to select a project with the relevant dependent projects and the --no-project-recurse flag.
   B. While analyzing the graphml file.
   Do we want so much variation that we as a small team should support?

@ajmooij What is your opinion? How is this realized in the C++ variant?