title: Rstudio can't find devtools
body: <p>I am trying to install R devtools, but RStudio can't find the library. I came across <a href="https://stackoverflow.com/questions/19885381/rtools-not-being-detected-by-r">this SO post</a> and <a href="https://github.com/stan-dev/rstan/issues/101" rel="nofollow noreferrer">this github discussion</a> which together might mean it is a Cygwin issue, but I have tried uninstalling git (and therefore my Cygwin copy) and reinstalling Rtools with no luck. Does anyone have ideas about other things to try?</p>
  
  <p>My system:
  <li>Windows 10 with GIT bash installed (therefore Cygwin as well)
  <li>RStudio version 0.99.902
  <li>R version 3.3</p>
  
  <pre><code>&gt; install.packages("devtools")
  &gt; library(devtools)
  &gt; find_rtools(T)
  Error: running command '"C:/PROGRA~1/R/R-33~1.0/bin/x64/R" --no-site-file --no-environ --no-save --no-restore --quiet CMD config CC' had status 127
  </code></pre>
  
  <p>My path (from within RStudio):</p>
  
  <pre><code>&gt; Sys.getenv()['PATH']
  PATH                                           C:\Program
                                                 Files\R\R-3.3.0\bin\x64;C:\ProgramData\Oracle\Java\javapath;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program
                                                 Files\Git\cmd;C:\cygwin32;C:\Program Files\Git\mingw64\bin;C:\Program
                                                 Files\Git\usr\bin;C:\Users\king\Desktop\_REPOS\misc\stock_analysis\forex\oanda\ruby;C:\Users\king\.dnx\bin;C:\Program
                                                 Files\Microsoft DNX\Dnvm\;C:\Ruby22-x64\bin
  </code></pre>