Unable to deploy shiny app when using github package

Hi everyone,
I'm trying to deploy my shiny app to the shiny-server but it's giving an error as
Error: Unhandled Exception: Child Task 910178654 failed: Error building image: Error building dropClust (2.1.0). Build exited with non-zero status: 1
Execution halted
dropClust is GitHub package which I installed as:

install_github("debsin/dropClust", dependencies = T)

Although there are other GitHub packages like Harmony which did not give me any error. Can somebody tell me what should I do to solve this error?

There is usually more info than that "unhandled Exception: Child task..." blah blah blah. I just got the same error message and it turns out the github package wasn't importing all of its dependencies. If you scroll up, there should be more info.