Ability to declare a non-cran dependency

[gaborcsardi]

It would be nice to be able to declare a non-cran dependency, in a way that is detected by dependencies(), without creating a full DESCRIPTION file.

One way would be to put something like

# pak::pak("user/repo@branch")
library(repo)

into a deps.R file. AFAIK people already use these files as a convention to declare undetected CRAN(-like) dependencies, so this would be a natural addition.

We could also have an alternative syntax with renv::install(...) instead of the pak() call.

[kevinushey]

Spitballing, but some ideas:

library(package)  #* user/repo@branch

Alternatively, we could use some different function for loading packages and encode the remote as part of the call, e.g.

uses(
  package = "user/repo@branch",
  ...
)

[gaborcsardi]

I think there is value in being able to copy-paste the installation command, hence the pak::pak() and renv::install() syntax.