Store temporary sync files to system temp to avoid shared drive problems

[erpas]

There are many support tickets related to (mostly Windows) users having local project copy on a shared/network drive, be it SharePoint, OneDrive, Dropbox etc.

The point is that it interferes with our sync, that creates temp files and deletes them while OneDrive tries to read them, and then sync fails on that. I think the very first thing we need to do is to put temporary files to the system-wide temporary folder, that should in my opinion already fix most of the issues

https://lutraconsulting.slack.com/archives/CDGBLDTL6/p1750863533282459?thread_ts=1750863391.580239&cid=CDGBLDTL6

Fix:

• Use system-wise temporary folder for storing temp sync data instead of the hidden .mergin folder

Outdated description

Shall we add a check/warning in the New Project wizard if local project path:

• is on a network drive (for Windows users, please see this SO page)
• is part of SharePoint/OneDrive/Dropbox

Examples of shared paths on Windows:

C:\Users\<user>\OneDrive\Desktop\
D:\Dropbox\[Shared Folder] aaa\
C:\Users\<user>\Dropbox\Mein PC\

[erpas]

Users keep storing their projects in shared folders. Would it be possible to warn them before they save / download a project to be aware of this limitation?

Related ticket: #324

[raherin]

This is still an issue that is impacting quite a few users

[RastoHu]

After discussion with @JanCaha this will be tested together with MerginMaps/python-api-client#259