The description of the type argument in the documentation of the pkgDep() function is possibly confusing.

[indenkun]

Dear Developers and Maintainers.

The type argument in the documentation of the pkgDep() function explains that

Possible values are (currently) "source", "mac.binary" and "win.binary": the binary types can be listed and downloaded but not installed on other platforms. Passed to download.packages().

If I follow this description and try to specify a binary package for macOS with type = ‘mac.binary, I get the following error.

miniCRAN::pkgDep("miniCRAN", type = "mac.binary")
#> Warning: unable to access index for repository https://cran.rstudio.com/bin/macosx/contrib/4.4:
#>   cannot open URL 'https://cran.rstudio.com/bin/macosx/contrib/4.4/PACKAGES'
#> Error: Unable to retrieve mac.binary package miniCRAN from https://cran.rstudio.com/

Of course, this can be solved by setting type = "mac.binary.big-sur-arm64" and so on, but this solution cannot be read from this document and is somewhat difficult for the novice user.

The type argument here is explained, for example, as follows,

Possible values are (currently) "source", "win.binary" and "mac.binary" or "mac.binary.*", where The last part of * is optional and currently only used on macOS to disambiguate builds targetting different macOS versions or architectures. Example values: "mac.binary.big-sur-arm64" for macOS 11 ( Big Sur) arm64 binaries. The binary types can be listed and downloaded but not installed on other platforms. Passed to download.packages().

and so on, would provide a solution.

Please consider.