Empty / unnamed repositories can crash `renv::snapshot()`

[kamilzyla]

Problem

The following sequence of commands:

options(repos = NULL)
renv::init()
options(repos = "https://cloud.r-project.org")
renv::snapshot()

Will result in the following error:

Error in mapply(renv_lockfile_diff_impl, old, new, MoreArgs = list(compare = compare),  : 
  zero-length inputs cannot be mixed with those of non-zero length

Expected behavior

Renv should either save the unnamed repository (as it does if we don't first set repos = NULL) or refuse to use unnamed repository with a meaningful message.

[sdcharle]

I'm getting that weird error message and this is the only link I found :/

[kevinushey]

Use a named repository, e.g.

options(repos = c(CRAN = "https://cloud.r-project.org"))