Adding support for sftp to RCurl

While trying to download data from an FTP with the sftp protocol from R I encountered the folllowing error on my mac:

Error in function (type, msg, asError = TRUE)  : 
  Protocol "sftp" not supported or disabled in libcurl

The easiest way to fix this for me was performing the following steps:

brew install curl --with-libssh2

Then check whether sftp is now among the list of supported protocols:

/usr/local/opt/curl/bin/curl -V

Link to the new version of curl you installed:

brew link --force curl

Re-install RCurl from source:

install.packages("RCurl", type = "source")

And finally check if sftp is now supported: