Projectile ignores all File markers except .git

Question

I recently started working with a few projects that either don't have a .git directory in their root, or are a subdirectory of a git repo, e.g.

parent-project/
  |- .git
  +- my-project/
       |- Cargo.toml
       +- src/main.rs

And in all cases I found that Projectile sets the root to the nearest directory containing .git, ignoring all other file markers (Cargo.toml, stack.yaml, etc.) along the way. (In the example above, opening main.rs sets the project root to parent-project instead of my-project).

The Projectile documentation suggests that this should not be the case, so I'm wondering how I can either manually set the project root for each project, or configure Projectile to use the actual file markers.