Checking for newly installed QGIS version

[florisvdh]

After upgrading QGIS 3.22 to 3.24, the cache is not updated and one still gets (on Linux Mint 20):

> library(qgisprocess)
Using 'qgis_process' at '/usr/bin/qgis_process'.
QGIS version: 3.22.3-Białowieża
Configuration loaded from '~/.cache/R-qgisprocess/cache-0.0.0.9000.rds'
Run `qgis_configure()` for details.
Using JSON for output serialization

When loading qgisprocess, it would probably be best to always check whether a new QGIS version is installed compared to the cached version, before loading the cache. In case of a new version, the cache is to be refreshed (by running qgis_configure()). And in that case, GRASS and SAGA providers (and perhaps other plugins), if they're available, could be enabled if not already so (see #93), before running the reconfiguration.

[paleolimbot]

Good point! On MacOS the path changes for most version updates, so I didn't catch it. The current trigger for the cache is:

https://github.com/paleolimbot/qgisprocess/blob/master/R/qgis-configure.R#L101

...but should probably be rlang::hash(list(<all the things that should trigger an update>))

[florisvdh]

A proposed fix (cache rebuilding) is in PR #110, which also gives some feedback to the user about changed QGIS version or path.