title: CLibraryError: error parsing unit database
body: <p>I'm using a software called <code>visan</code>. It's actually a python-module and installable via conda with <code>conda install -c stcorp visan</code>. It comes with a gui and seems to be great for working with remote sensing data. When I use a function from the package <code>harp</code> to import data it always throws me this error:</p>
  
  <pre><code>Traceback (most recent call last):
    File "&lt;input&gt;", line 1, in &lt;module&gt;
    File "/home/user/miniconda3/envs/visan/lib/python3.7/site-packages/harp/_harppy.py", line 1134, in import_product
      raise CLibraryError()
  harp._harppy.CLibraryError: error parsing unit database (/home/user/miniconda3/envs/visan/share/harp/udunits2.xml)
  </code></pre>
  
  <p>If it matters: I'm using ubuntu 18.04;) I can however start <code>python</code> from bash and import and call <code>harp.import_product</code> without a problem. Though I don't know how to use sume functionality from the command line (e.g. the function <code>wplot</code>). I'm a little lost how to approach this error:/</p>