[postgis-users] Problem with "undefined symbol: GEOSMakeValid_r"

[Marco Boeringa]

Hi all,

I hope someone has a recommendation for how to solve this:

When I attempted to upgrade my 19.10 Ubuntu installation to 20.04, I 
first ran into an issue that I couldn't run the Ubuntu upgrade 
installer, unless I uninstalled PostGIS 2.5 first. It complained about 
PostGIS being on the "black list for removal" or something similar. So, 
I finally decided to uninstall the PostGIS 2.5 through the Synaptics 
Package manager of Ubuntu, after which I was able to upgrade to 20.04 Focal.

I then attempted to re-install PostGIS 2.5 from the Synaptic Pacakage 
manager again. After several attempts, I now have it installed, and I 
can access spatial data from the existing PostgreSQL 11 database using 
e.g. DBeaver.

However, as part of my code, I had a call to the 
"PostGIS_Full_Version()" function, and that now fails with the error 
attached below. Is this still an indication the PostGIS 2.5 install is 
somehow broken? I have already tried to re-install "libgdal26", as is 
referenced in the error message, but to no avail.

I have also attempted to install the "postgresql-11-postgis-3" and 
"postgresql-11-postgis-3-scripts" packages, in the hope of being able to 
solve the issue by upgrading PostGIS, but that failed as well, with 
Synaptic showing an error message and complaining about a shared library 
/ application that is also in the PostGIS 2.5 install and that "could 
not be overwritten" (file 
"usr/share/postgresql/11/applications/shp2pgsql-gui.desktop")

Marco

SQL Error [XX000]: ERROR: could not load library 
"/usr/lib/postgresql/11/lib/rtpostgis-2.5.so": /usr/lib/libgdal.so.26: 
undefined symbol: GEOSMakeValid_r
   Where: SQL statement "SELECT public.postgis_gdal_version()"
PL/pgSQL function postgis_full_version() line 34 at SQL statement