Deploying on shinyapps.io: A package dependency should not be required, yet Shiny asks for it

Hi

I am building a Shiny application based on an unpublished package. I have, therefore, explicitly created stand-alone functions of parts of this unpublished package. Shiny call these functions when needed. On my local machine, Shiny is not calling this unpublished package. I have even uninstalled this package to make sure that Shiny is independently functioning.

Yet, when I deploy this package to shinyapps.io, I face an error about this unpublished package is required.

I suspected that an earlier Shiny deployment of this app might have interfered and that this dependencies is an echo. So I removed that earlier version to make sure that this app is not interfering with the new app. But the same problem persists.

In summary, a package dependency should not be required, yet Shinyapps asks for it.Any idea of what is going on?

Not sure how to write a reproducible example of this particular issue.

(NB, I have posted this question as well at: https://github.com/rstudio/shiny/issues/2527)