title: Installing a package offline from GitHub
body: <p>I'm trying to port some packages to an R installation on an offline (Windows) computer.</p>
  <p>From CRAN (let's say <code>data.table</code>), the process: 1) download .zip on separate online computer 2) thumb drive -&gt; offline computer 3) install via <code>install.packages(&quot;....zip&quot;...)</code> works exactly as expected.</p>
  <p>However, this process broke down when I tried to install from GitHub.</p>
  <p>When I run <code>install.packages</code> (note: I'm using <code>type=&quot;binary&quot;</code> and <code>repos=NULL</code>; <code>type=&quot;win.binary&quot;</code> does nothing either) on the zip file (obtained by going to the package page, e.g. <a href="https://github.com/Rdatatable/data.table" rel="noreferrer">https://github.com/Rdatatable/data.table</a>, and using the &quot;Download .zip&quot; function), something goes wrong.</p>
  <p>There's no error message (and nothing new from setting <code>verbose=TRUE</code>), and the package folder is added to my library (i.e., I can see the folder named &quot;data.table-master&quot; when I navigate there), but <code>library(data.table)</code> results in the error: &quot;there is no package called <code>data.table</code>&quot;. I also noticed that, while the installation from CRAN finishes with &quot;package <code>data.table</code> successfully unpacked and MD5 sums checked&quot;, I get no such message from an attempted GitHub installation.</p>
  <p>What's going on here? I tried all possible leads in <code>?install.packages</code>, but given I'm not really getting an error message it's been hard to diagnose what exactly is the issue.</p>
  <p>More background: R version is 3.2.0. Hard to copy-paste <code>sessionInfo</code> since that computer's not online, not sure what else may be relevant.</p>
  <h1>Update:</h1>
  <p>Given @r2evans' comments below, I also tried using <code>type=&quot;source&quot;</code> with <code>install.packages</code>, and this didn't work either (same problem--despite having &quot;data.table-master&quot; folder in one of my <code>.libPaths()</code> addresses, <code>library(data.table)</code> gives the error that there's no such package).</p>
  <p>I did get some more output from using <code>verbose=TRUE</code> this time, however:</p>
  <blockquote>
  <p>system (cmd0): <code>C:/PROGRA~1/R/R-32~1.0/bin/x64/R CMD INSTALL</code></p>
  <p>1): succeeded <code>'C:/PROGRA~1/R/R-32~1.0/bin/x64/R CMD INSTALL -l &quot;C:\Users\Mike\Documents\R\win-library\3.2&quot; &quot;E:/data.table-master.zip&quot;'</code></p>
  </blockquote>