title: laspy cannot find laszip when is installed from source. laszip is in path
body: <p>I am working on a HPC environment and do not have root access. I installed laszip from source.</p>
  
  <h1>Install laszip from source</h1>
  
  <pre><code>module load git
  git clone https://github.com/LASzip/LASzip.git
  git checkout tags/2.0.2
  cd LASzip
  </code></pre>
  
  <p>Make files in the build directory.</p>
  
  <pre><code>mkdir build
  cd build
  module load cmake
  module load gcc
  cmake .. -DCMAKE_INSTALL_PREFIX=/home/b.weinstein/LASzip/build 
  make
  make install
  </code></pre>
  
  <p>Add paths</p>
  
  <pre><code>export LD_LIBRARY_PATH="/home/b.weinstein/LASzip/build/lib:$LD_LIBRARY_PATH"
  export PATH="/home/b.weinstein/LASzip/build/bin:$PATH"
  </code></pre>
  
  <p>Make sure it works locally</p>
  
  <pre><code>(pangeo) [b.weinstein@c30a-s26 bin]$ pwd
  /home/b.weinstein/LASzip/build/bin
  (pangeo) [b.weinstein@c30a-s26 bin]$ laszip-config --version
  2.0.2
  </code></pre>
  
  <p>Go to a new directory to test linking</p>
  
  <pre><code>cd ~
  (pangeo) [b.weinstein@c30a-s26 ~]$ laszip-config --version
  2.0.2
  </code></pre>
  
  <h1>Test from python</h1>
  
  <pre><code>(pangeo) [b.weinstein@c30a-s26 ~]$ python
  Python 3.6.4 | packaged by conda-forge | (default, Dec 23 2017, 16:31:06) 
  [GCC 4.8.2 20140120 (Red Hat 4.8.2-15)] on linux
  Type "help", "copyright", "credits" or "license" for more information.
  &gt;&gt;&gt; import laspy
  &gt;&gt;&gt; test_file=laspy.file.File("/ufrc/ewhite/s.marconi/NeonData/2017_Campaign/D03/OSBS/L1/DiscreteLidar/ClassifiedPointCloud/NEON_D03_OSBS_DP1_412000_3283000_classified_point_cloud.laz")
  Traceback (most recent call last):
    File "/home/b.weinstein/miniconda3/envs/pangeo/lib/python3.6/site-packages/laspy/base.py", line 204, in map
      self._mmap=FakeMmap(self.filename)
    File "/home/b.weinstein/miniconda3/envs/pangeo/lib/python3.6/site-packages/laspy/base.py", line 57, in __init__
      data = read_compressed(filename)
    File "/home/b.weinstein/miniconda3/envs/pangeo/lib/python3.6/site-packages/laspy/base.py", line 37, in read_compressed
      raise(laspy.util.LaspyException("Laszip was not found on the system"))
  laspy.util.LaspyException: Laszip was not found on the system
  </code></pre>
  
  <p>How can I tell laspy where to look for laszip? Is this a pythonpath issue?</p>