Fixing mismatch between PROJ version and proj.db?

Question

When transforming the CRS in QGIS, I get the following error: No transform available between EPSG:32722 and Custom CRS (or any CRS). When I click on Details, I read the following message:

No transform is available between EPSG:32722 - WGS 84 / UTM zone 22S and Custom CRS: GEOGCRS["unknown",DATUM["unknown",ELLIPSOID["WGS 8….

proj_create_operations: SQLite error on SELECT name, type, coordinate_system_auth_name, coordinate_system_code, datum_auth_name, datum_code, area_of_use_auth_name, area_of_use_code, text_definition, deprecated FROM geodetic_crs WHERE auth_name = ? AND code = ?: no such column: area_of_use_auth_name

After some searching online, I found that the problem is likely due to a mismatch between the PROJ version and the proj.db: "You're likely using a PROJ < 8 library with a proj.db from PROJ 7.2 or 8. Check PROJ_LIB" (https://lists.osgeo.org/pipermail/gdal-dev/2020-December/053177.html).

EDIT: I might have caused this problem myself when I tried to solve another problem related to dpkg. I used the solution offered in this thread: https://askubuntu.com/questions/1309161/dpkg-error-processing-package-qgis-providers-configure. This might have led to the current error I'm describing here.

However, I cannot find the solution for fixing this mismatch. What should I do to make the PROJ library work again? Downgrade the current installation, or do something with the proj.db?

QGIS installation information:

Output of the command proj -v:

proj_create: unrecognized format / unknown name
Rel. 8.2.0, November 1st, 2021
<proj>: 
projection initialization failure
cause: Unknown error (code 4096)
program abnormally terminated

Answer 1

Looks like there is a mess with different versions of PROJ. That's bad. And you are having problems to install the package 6.3.1.

As a first try you can get the file proj.db from the tarball for that release https://github.com/OSGeo/PROJ/releases/tag/6.3.1 and set the environment variable PROJ_LIB pointing to the directory where you place it. If you want to use grid files, they should be in that env var as well (separate the folder paths with : in your case -linux-)

If that works, try to set a more stable configuration for your system.

Maybe you need as well the library (libproj.so.15.3.1). In this case using LD_LIBRARY_PATH may help you.

Answer 2

I realise this is an old question, but I had to solve the same problem of a mismatching proj.db version and have succeeded in a workaround.

I had to:

• download the deb package containing the matching proj.db
• Manually install the database to a custom location
• When running QGIS, set the PROJ_LIB environment variable to point at the matching proj.db

Example manual installation is:

mkdir proj
apt download proj-data=6.3.1-1
dpkg-deb --extract proj-data_6.3.1-1_all.deb ./proj
sudo mkdir /usr/share/proj-6.3.1
sudo cp ./proj/usr/share/proj/* /usr/share/proj-6.3.1
rm proj-data_6.3.1-1_all.deb
rm -r proj

To run QGIS then use:

PROJ_LIB=/usr/share/proj-6.3.1 qgis

My problem was caused by having QGIS 3.26.3 (compiled against proj 6.3.1) and proj 7.2.1.