title: R package not found, but present in correct library
body: <p>I have a problem with the R package "gridExtra". Everything is ok, when I go into R and load it, but when I execute a python script, which among others also loads this package, everything stops. I don't understand it, since I checked the library and the right library is selected.</p>
  
  <p>It's a little complicated, because the script is from someone else. It can be accessed from here: <a href="https://github.com/guigolab/ggsashimi/blob/master/sashimi-plot.py" rel="nofollow noreferrer">https://github.com/guigolab/ggsashimi/blob/master/sashimi-plot.py</a>. The package is loaded at row 430. Loading the previous packages was no problem, after installing them into the custom library. During the python script, a custom R script is generated and executed. Within this R script, the package is loaded usign the function <code>library(gridExtra)</code>.</p>
  
  <p>The error message is:</p>
  
  <p><code>Error in library(gridExtra) : there is no package called â€˜gridExtraâ€™
  Execution halted</code></p>
  
  <p>I checked, if the generated R script really accesses the right library and it does, so there is no problem with the library selection.</p>