Why is R prompting me and failing on `update.packages()`? <p>I'm new to R and I've compiled it myself on Ubuntu 14.04.3 (x64). Note, I am up to date with the R source: </p> <pre><code>blong@work:~/Documents/Work/REPOS__svn/R/R-3-2-branch$ svn info |head -n 7 Path: . Working Copy Root Path: /home/blong/Documents/Work/REPOS__svn/R/R-3-2-branch URL: https://svn.r-project.org/R/branches/R-3-2-branch Relative URL: ^/branches/R-3-2-branch Repository Root: https://svn.r-project.org/R Repository UUID: 00db46b3-68df-0310-9c12-caf00c1e9a41 Revision: 69384 blong@work:~/Documents/Work/REPOS__svn/R/R-3-2-branch$ svn status -u Status against revision: 69392 </code></pre> <p>Running <code>configure</code> and <code>make</code> in R's 3.2.2 branch have completed successfully and I'm able to use a variety of packages within an R session. However, I'd like to check that all of my libraries are up to date. In R 3.2.2 , I'm invoking <code>update.packages()</code>. When the function is invoked, I'm prompted to select a CRAN mirror : </p> <p><a href="https://i.stack.imgur.com/0LKME.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/0LKME.png" alt="CRAN mirror selection dialog"></a></p> <p>Assuming everything is fine and this is a non-issue, I select the main ("<code>O-Cloud [https]</code>") mirror from the dialog. The dialog closes and I'm returned to my R prompt with a duplicate message saying "<code>unsupported URL scheme</code>".</p> <p>Simultaneously, I receive an error in my R session upon invoking <code>update.packages()</code>: </p> <pre><code>&gt; getOption("repos") CRAN "@CRAN@" &gt; update.packages() --- Please select a CRAN mirror for use in this session --- Error in download.file(url, destfile = f, quiet = TRUE) : unsupported URL scheme Warning: unable to access index for repository https://cran.rstudio.com/src/contrib: unsupported URL scheme &gt; </code></pre> <p>Considering that perhaps this is an issue with HTTPS, I try a non-SSL mirror and similarly nothing happens (perhaps there are no updates, but I'd like a message that tells me this). However, this time I don't receive the second "unsupported URL scheme" message after the dialog closes : </p> <pre><code>&gt; update.packages() --- Please select a CRAN mirror for use in this session --- Error in download.file(url, destfile = f, quiet = TRUE) : unsupported URL scheme &gt; </code></pre> <p>It seems that under the hood, R uses a library called RCurl to do some of it's HTTP/S interaction. As far as I can tell, I'm using a supported version of curl / libcurl : </p> <pre><code>blong@work:~$ curl --version curl 7.35.0 (x86_64-pc-linux-gnu) libcurl/7.35.0 OpenSSL/1.0.1f zlib/1.2.8 libidn/1.28 librtmp/2.3 Protocols: dict file ftp ftps gopher http https imap imaps ldap ldaps pop3 pop3s rtmp rtsp smtp smtps telnet tftp Features: AsynchDNS GSS-Negotiate IDN IPv6 Largefile NTLM NTLM_WB SSL libz TLS-SRP </code></pre> <p>Any thoughts on this? It seems similar to this <a href="http://r.789695.n4.nabble.com/update-packages-behavior-td4711966.html" rel="nofollow noreferrer">mailing list discussion</a>, but I'm not sure if this is an issue or I'm doing something wrong.</p>