title: Creating R package, Warning: package ‘---’ was built under R version 3.1.2
body: <p>I am creating my own R package which depends on a function defined in R-package named fOption.
  My NAMESPACE file has a line:</p>
  
  <pre><code>  import(fOptions)
  </code></pre>
  
  <p>My DESCRIPTION file has a line:</p>
  
  <pre><code>  Depends:  fOptions
  </code></pre>
  
  <p>However, when I compile my R package using R CMD CHECL --as-cran option from the terminal, I get the following warning messages:</p>
  
  <pre><code>   Found the following significant warnings:
     Warning: package ‘timeDate’ was built under R version 3.1.2
     Warning: package ‘timeSeries’ was built under R version 3.1.2
     Warning: package ‘fBasics’ was built under R version 3.1.2
  </code></pre>
  
  <p>I found that these are dependencies of fOptions as its description file says:</p>
  
  <pre><code>  Depends: methods, timeDate, timeSeries, fBasics
  </code></pre>
  
  <p>Does this mean that I cannot create my R package that depend on this particular R package (fOption)?</p>
  
  <p>I am using OS X Version 10.9.4 and My R version is 3.1.1 (2014-07-10) -- "Sock it to Me".</p>