I have 2 branches of the same app installed (current one is installed via user, branch is installed via system, and is slightly older), and I saw they use the same .var/app directory, could using the system installed branch version conflict with my current installation, as they use the same directories despite being different versions?
Can the configuration directory of an app conflict if you have 2 branches of the same app installed?
that depends on if they use their data, settings, and cache differently, and if said differences are on specific files
for Jorts i had a saved_state.json. At some point the objects saved in it had a new key (an Int mirror of an old key, so for about a year Jorts saved the key twice to ease any migration).
if there were two versions, witht about one year and a half of updates apart, and both regularly used, the old version and new version would both not be able to read that key from a saved_state written by the other, and rewrite the saved_state.json with their blankslate values, boinking data for the other
Since this was for color themes, if i didnt plan for the case the value is nowhere to be found, every sticky note would appear with a very corrupted theme
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this difference in settings and data files would be more of an issue for standard packagings like deb, for distros like debian, where you jump versions like several years into the future at once. Flatpaks are amazing exactly because i control updates, and dont have to plan for “oh dang this three year old version is still in use in debian i cant do that or everything will break next debian” and do super complex multi version legacy drifting