Precompilation does not see added dependecy

I have added “Infiltrator” as a dependency to my locally developed package “SpinGauss”.
However, it produced an error at precompilation stage.
When I run import Pkg; Pkg.precompile() as suggested by the error log, I get the following:

Failed to precompile
ERROR: LoadError: ArgumentError: Package SpinGauss does not have Inflitrator in its dependencies:

  • If you have SpinGauss checked out for development and have
    added Inflitrator as a dependency but haven’t updated your primary
    environment’s manifest file, try Pkg.resolve().
  • Otherwise you may need to report an issue with SpinGauss

This is really strange. The error says that I didn’t add “Infiltrator” to dependencies, although I just did.
I tried to run Pkg.resolve() but it did not help. I also tried to delete “Manifest.toml” and [deps] section of “Project.toml” and add all the dependencies again, but I still get the same error.

How do I fix this?