title: debian Tesseract TESSDATA_PREFIX issue
body: <p>I'm currently running an error with my Python program using Tesseract. For now I do my test on Ubuntu and I have no problem (Tesseract v4 is on the official repo). I want now to try it under Debian and because official repo doesn't have the v4 of Tesseract, I have to compile from source Tesseract. I do it like this  : </p>
  
  <pre><code>git clone -b4.0.0 https://github.com/tesseract-ocr/tesseract
  cd tesseract
  mkdir build &amp;&amp; cd build
  cmake .. &amp;&amp; make
  make install
  </code></pre>
  
  <p>Then I do this : </p>
  
  <pre><code>export LD_LIBRARY_PATH=/usr/local/lib  
  export TESSDATA_PREFIX=/usr/share/tesseract-ocr/
  </code></pre>
  
  <p>My tessdata prefix contain all the trained language but I have the following error : </p>
  
  <blockquote>
    <p>pytesseract.pytesseract.TesseractError: (1, 'Error opening data file ./fra.traineddata Please make sure the TESSDATA_PREFIX environment variable is set to your "tessdata" directory. Failed loading language \'fra\' Tesseract couldn\'t load any languages! Could not initialize tesseract.')</p>
  </blockquote>
  
  <p>I try to put the TESSDATA_PREFIX onto the ~/.profile, add it to the PATH var in the same file, but I still have the issue</p>
  
  <p>Thanks in advance for your help</p>