<p class="MsoNormal gmail_msg" style="color:rgb(49,49,49);word-spacing:1px">Dear all </p><p class="MsoNormal gmail_msg" style="color:rgb(49,49,49);word-spacing:1px">I am using VTK 7.1 for saving visualization data using XDMF2 format. Current files produced are big, so I enabled XDMF_USE GZIP option hoping that it activates the compression on the .h5 file.  However, during compilation I get error messages due to undefined references (it seems that XDMF2 is not depending on ZLIB). The compiler output  is: </p><p class="MsoNormal gmail_msg" style="color:rgb(49,49,49);word-spacing:1px"><u class="gmail_msg"></u></p><p class="MsoNormal gmail_msg" style="color:rgb(49,49,49);word-spacing:1px">CMakeFiles/vtkxdmf2.dir/gzstream.cxx.o: In function `gzstreambuf::open(char const*, int)':                                                                                                                             <u class="gmail_msg"></u></p><p class="MsoNormal gmail_msg" style="color:rgb(49,49,49);word-spacing:1px">vtk/VTK-7.1.0/ThirdParty/xdmf2/vtkxdmf2/libsrc/gzstream.cxx:61: undefined reference to `gzopen'                                                                                                              <u class="gmail_msg"></u><u class="gmail_msg"></u></p><p class="MsoNormal gmail_msg" style="color:rgb(49,49,49);word-spacing:1px">CMakeFiles/vtkxdmf2.dir/gzstream.cxx.o: In function `gzstreambuf::close()':                                                                                                                                                                 <u class="gmail_msg"></u><u class="gmail_msg"></u></p><p class="MsoNormal gmail_msg" style="color:rgb(49,49,49);word-spacing:1px">vtk/VTK-7.1.0/ThirdParty/xdmf2/vtkxdmf2/libsrc/gzstream.cxx:72: undefined reference to `gzclose'                                                                                                             <u class="gmail_msg"></u><u class="gmail_msg"></u></p><p class="MsoNormal gmail_msg" style="color:rgb(49,49,49);word-spacing:1px">CMakeFiles/vtkxdmf2.dir/gzstream.cxx.o: In function `gzstreambuf::underflow()':                                                                                                                                                             <u class="gmail_msg"></u><u class="gmail_msg"></u></p><p class="MsoNormal gmail_msg" style="color:rgb(49,49,49);word-spacing:1px">vtk/VTK-7.1.0/ThirdParty/xdmf2/vtkxdmf2/libsrc/gzstream.cxx:90: undefined reference to `gzread'                                                                                                              <u class="gmail_msg"></u><u class="gmail_msg"></u></p><p class="MsoNormal gmail_msg" style="color:rgb(49,49,49);word-spacing:1px">CMakeFiles/vtkxdmf2.dir/gzstream.cxx.o: In function `gzstreambuf::flush_buffer()':                                                                                                                                                          <u class="gmail_msg"></u><u class="gmail_msg"></u></p><p class="MsoNormal gmail_msg" style="color:rgb(49,49,49);word-spacing:1px">vtk/VTK-7.1.0/ThirdParty/xdmf2/vtkxdmf2/libsrc/gzstream.cxx:107: undefined reference to `gzwrite'                                                                                                            <u class="gmail_msg"></u><u class="gmail_msg"></u></p><p class="MsoNormal gmail_msg" style="color:rgb(49,49,49);word-spacing:1px">collect2: error: ld returned 1 exit status                                                                                                                                                                               <u class="gmail_msg"></u><u class="gmail_msg"></u></p><p class="MsoNormal gmail_msg" style="color:rgb(49,49,49);word-spacing:1px">gmake[2]: *** [lib/libvtkxdmf2-7.1.so.1] Error 1                                                                                                                                                                                             <u class="gmail_msg"></u><u class="gmail_msg"></u></p><p class="MsoNormal gmail_msg" style="color:rgb(49,49,49);word-spacing:1px">gmake[1]: *** [ThirdParty/xdmf2/vtkxdmf2/libsrc/CMakeFiles/vtkxdmf2.dir/all] Error 2  <u class="gmail_msg"></u><u class="gmail_msg"></u></p><p class="MsoNormal gmail_msg" style="color:rgb(49,49,49);word-spacing:1px"><u class="gmail_msg"></u> <u class="gmail_msg"></u></p><p class="MsoNormal gmail_msg" style="color:rgb(49,49,49);word-spacing:1px">How can I solve that issue?<u class="gmail_msg"></u><u class="gmail_msg"></u></p><p class="MsoNormal gmail_msg" style="color:rgb(49,49,49);word-spacing:1px">What do I have to do so vtkXdmfWriter creates a compressed  .h5 file ? </p><p class="MsoNormal gmail_msg" style="color:rgb(49,49,49);word-spacing:1px"><u class="gmail_msg"></u></p><p class="MsoNormal gmail_msg" style="color:rgb(49,49,49);word-spacing:1px"><u class="gmail_msg"></u> <u class="gmail_msg"></u></p><p class="MsoNormal gmail_msg" style="color:rgb(49,49,49);word-spacing:1px">Thank you!</p><p class="MsoNormal gmail_msg" style="color:rgb(49,49,49);word-spacing:1px"><u class="gmail_msg"></u> </p>