Do you have logs of this happening in Proton? (PROTON_LOG=1)
OK! I managed to replicate the issue, I destroyed the prefix and reinstalled Uplay under it so it would be unpatched.
Renabled FSYNC and ESYNC.
Enabled logs and launched.
I let it run at "Looking for patches" For several minutes. (When working correctly it takes seconds.)
I disabled esync and fsync and launched and within seconds it started downloading, getting past the "Looking for patches".
I then killed it mid download and captured this log!
steam-582160-no-esync.log
Only fsync needs to be disabled, I have this issue as well but in lutris. (for far cry 6)
I've seen that Uplay complains about entry point in libcef.dll after upgrade, but after stopping and starting again it works fine. So the "relaunch" (switch to newer version) might be the problem in those cases, not the upgrade itself since it works fine after.
proton experimentalx1 2022-02PROTON_LOG=1)x1 2022-02libcef.dllx1 2022-02
Your system information
Please describe your issue in as much detail as possible:
Tried two games (Assassin's Creed Origins and Odyssey) In Proton-Experimental
Both needed a Uplay upgrade.
Disabling ESYNC and FSYNC allowed the upgrade to succeed immediately after trying several other things.
Uplay launches fine with them enabled unless an update is needed.
Others have reported it can update with them enabled, but it may take several tried, seems to be luck/random.
Steps for reproducing this issue:
Download a fresh Uplay game/clear compat data.
Try to launch the game and Uplay will attempt to update.
It may work, it may not.
If it doesn't it is usually consistent and disabling esync/fsync will make it work right away (I did not try it individually)