[R-sig-Geo] Installation of proj4 v6 on Ubuntu 18.04 Error: proj/epsg not found

[Tomislav Hengl]

Dear R-sig-geo,

I am trying to install proj4 v6 on Ubuntu 18.04 bionic. I though I can 
install it simply by following the ubuntugis steps 
(https://mothergeo-py.readthedocs.io/en/latest/development/how-to/gdal-ubuntu-pkg.html) 
but this does not lead to newest version of proj4 v6.

Then I have tried to follow the proj6 steps 
(https://proj.org/install.html#install) which indicate that I should do 
it via the Anaconda installer. After I installed proj4 v6 from conda I get:

$ which proj
/home/tomislav/anaconda2/bin/proj

$  proj -V
Rel. 6.2.0, September 1st, 2019
<proj>:
projection initialization failure
cause: no arguments in initialization list
program abnormally terminated

After that I've added the 'PROJ_LIB = /home/tomislav/anaconda2/bin/proj
' to my .Renviron file and then I get:

install.packages("rgdal")
Installing package into ‘/home/tomislav/R/x86_64-pc-linux-gnu-library/3.5’
(as ‘lib’ is unspecified)
...
checking PROJ.4: epsg found and readable... no
Error: proj/epsg not found
Either install missing proj support files, for example
the proj-nad and proj-epsg RPMs on systems using RPMs,
or if installed but not autodetected, set PROJ_LIB to the
correct path, and if need be use the --with-proj-share=
configure argument.
ERROR: configuration failed for package ‘rgdal’
* removing ‘/home/tomislav/R/x86_64-pc-linux-gnu-library/3.5/rgdal’
Warning in install.packages :
   installation of package ‘rgdal’ had non-zero exit status

$gdalinfo --version
GDAL 2.4.0, released 2018/12/14

What am I doing wrong? Which tutorial / documentation do you advise to 
install proj4 v6 and rgdal package on Ubuntu?

thank you (especially you Roger!),

T. Hengl