Mill omits projects when generating a BSP project when you have a foreign modules with same names as in project

[arturaz]

Repository with the reproduction: https://github.com/arturaz/bug-report-mill-foreign-modules-with-same-name

Steps:

• Open the repo with VSCode+Metals.
• Use mill-bsp
• You will see incomplete build definition, notice that shared is missing (things work fine in bloop mode).
  

Workaround:

• Rename /shared to /shared2 (and accordingly in /build.sc), reopen the project, things will work:
  

Related discussion: https://discordapp.com/channels/632150470000902164/940067748103487558/1256251618568175626