large directories in tempdir cause error with NULL root

[aronatkins]

t <- tempfile()
dir.create(t)
for (each in seq_len(1001)) { writeLines(character(0), file.path(t, paste0(each, ".txt")))}
renv::dependencies(t)
#> Error in dirname(root): a character vector argument expected

^{Created on 2023-08-22 with reprex v2.0.2}

This happens because renv:::renv_dependencies_root() returns NULL when provided the temporary directory as its path.

renv/R/dependencies.R

Lines 218 to 219 in ac7126d

	path <- renv_path_normalize(path, mustWork = TRUE)
	root <- root %||% renv_dependencies_root(path)

This is the underlying issue causing rstudio/rsconnect#968

[aronatkins]

Workaround is to set renv.config.dependencies.limit.

options(renv.config.dependencies.limit = 10000)

Bypassing the "large directory" handling lets renv::dependencies() complete.

[aronatkins]

This problem can be avoided by passing in a root argument to renv::dependencies():

renv::dependencies(t, root = t)

[kevinushey]

I think it ultimately comes down to this:

> renv:::renv_dependencies_root(t)
NULL

So, I think that setting root is the right solution here.