title: libgdal.so.20 issue centos rgdal
body: <p>Can someone help me to understanding what is the problem of rgdal ? </p>
  
  <p>I installed gdal 2 for centos 6 64 bits but i didn't succeed to install rgdal.
  I tried to figure out what is the issue but i didn't found anything useful on the internet . </p>
  
  <p>this is Rstudio-server console:</p>
  
  <pre><code> install.packages("rgdal")
   Installing package into ‘/home/admin/R/x86_64-redhat-linux-gnu-library/3.4’
   (as ‘lib’ is unspecified)
   essai de l'URL 'https://cran.rstudio.com/src/contrib/rgdal_1.2-18.tar.gz'
   Content type 'application/x-gzip' length 1650578 bytes (1.6 MB)
    ==================================================
   downloaded 1.6 MB
  
   * installing *source* package ‘rgdal’ ...
   ** package ‘rgdal’ correctement décompressé et sommes MD5 vérifiées
   configure: CC: gcc -m64 -std=gnu99
   configure: CXX: g++ -m64
   configure: rgdal: 1.2-18
   checking for /usr/bin/svnversion... yes
   configure: svn revision: 718
   checking for gdal-config... /usr/local/bin/gdal-config
   checking gdal-config usability... yes
   configure: GDAL: 2.2.3
   checking GDAL version &gt;= 1.6.3... yes
   checking gdal: linking with --libs only... yes
   checking GDAL: /usr/local/share/gdal/pcs.csv readable... yes
   configure: -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-        protector --param=ssp-buffer-size=4 -m64 -mtune=generic -fpic -fPIC  -I/usr/local/include
    checking proj_api.h presence and usability... yes
   ./proj_conf_test1: error while loading shared libraries: libgdal.so.20:   cannot open shared object file: No such file or directory
    checking PROJ.4 version: ... &lt; 4.8.0
  ./configure: line 2030: test: -eq: unary operator expected
    ./configure: line 2035: test: -ge: unary operator expected
    ./configure: line 2063: test: -ge: unary operator expected
    ./proj_conf_test2: error while loading shared libraries: libgdal.so.20:                cannot open shared object file: No such file or directory
    checking PROJ.4: epsg found and readable... yes
    ./configure: line 2138: test: -ge: unary operator expected
    ./proj_conf_test3: error while loading shared libraries: libgdal.so.20:    cannot open shared object file: No such file or directory
    checking PROJ.4: conus found and readable... yes
    configure: Package CPP flags:  -I/usr/local/include
    configure: Package LIBS:  -L/usr/local/lib -lgdal -lproj
    configure: creating ./config.status
    config.status: creating src/Makevars
    ** libs
    ogr_geom.cpp:39: attention : ‘mp_count_k0’ may be used uninitialized in this function
  
    ** R
    ** data
    ** inst
    ** preparing package for lazy loading
    ** help
    *** installing help indices
      converting help for package ‘rgdal’
        finding HTML links ... fini
        CRS-class                               html  
    ...
       closeDataset-methods                    html  
       displayDataset                          html  
       llgrid                                  html  
       Rd warning: /tmp/RtmpTT9ff6/R.INSTALL19d55c4b60f4/rgdal/man/llgrid.Rd:11: missing file link ‘Spatial’
       Rd warning: /tmp/RtmpTT9ff6/R.INSTALL19d55c4b60f4/rgdal/man/llgrid.Rd:16: missing file link ‘gridat’
       Rd warning: /tmp/RtmpTT9ff6/R.INSTALL19d55c4b60f4/rgdal/man/llgrid.Rd:17: missing file link ‘gridat’
           make_EPSG                               html  
           nor2k                                   html  
           projInfo                                html  
           project                                 html  
           readGDAL                                html  
       Rd warning: /tmp/RtmpTT9ff6/R.INSTALL19d55c4b60f4/rgdal/man/readGDAL.Rd:136: missing file link ‘flipVertical’
           readOGR                                 html  
           showWKT                                 html  
           spTransform-methods                     html  
           wrappers                                html  
           writeOGR                                html  
       ** building package indices
       ** installing vignettes
       ** testing if installed package can be loaded
       Error: package or namespace load failed for ‘rgdal’ in          dyn.load(file, DLLpath = DLLpath, ...):
        impossible de charger l'objet partagé '/home/admin/R/x86_64-redhat-         linux-gnu-library/3.4/rgdal/libs/rgdal.so':
         libgdal.so.20: Ne peut ouvrir le fichier d'objet partagé: Aucun    fichier ou dossier de ce type
    Erreur : le chargement a échoué
   Exécution arrêtée
       ERROR: loading failed
       * removing ‘/home/admin/R/x86_64-redhat-linux-gnu-library/3.4/rgdal’
   Warning in install.packages :
     installation of package ‘rgdal’ had non-zero exit status
  
       The downloaded source packages are in
           ‘/tmp/RtmpBon7nM/downloaded_packages’
  </code></pre>
  
  <p>I tried to install dependencies of gdal and copying libgdal.so.20 to /user/lib64/ogdi whithout any success !*</p>
  
  <p>Thank you for you help</p>