title: R - What does "incomplete block on file" mean?
body: <p>I am using RStudio, and am trying to use packrat with my current project.
  I click the checkbox "Use packrat with this project" and press OK, where I get the following output from the console:</p>
  
  <pre><code>    &gt; packrat::init()
  Initializing packrat project in directory:
  - "/Users/Ash/Dropbox/Uni/2014/Thesis/Code/R"
  
  Adding these packages to packrat:
              _         
      packrat   0.4.0.12
  
  Fetching sources for packrat (0.4.0.12) ... Error in snapshotSources(project, activeRepos(project), allRecordsFlat) : 
    Errors occurred when fetching source files:
  Error in untar2(tarfile, files, list, exdir, restore_times) : 
    incomplete block on file
  </code></pre>
  
  <p>I can't find much on this error, but based on <a href="https://svn.r-project.org/R/trunk/src/library/utils/R/tar.R">this</a> code (searching for the error string, incomplete block on file), it seems this relates to an unexpected file length/size.</p>
  
  <p>I assume the download may be corrupt? But I have tried multiple times.</p>
  
  <p>Or perhaps I don't have the correct permissions? But the project file should have no issues here.</p>
  
  <p>Has anybody else had this issue?</p>