protonscr

Mixed-case DriverStore/FileRepository path for igdext64.dll duplicates Wine's driverstore folder and breaks Steam's "Move install folder"

protonopen
ValveSoftware/Proton#10270 · opened 2026-10-16 by mattjwood · updated 2026-10-17 · 1 comments · github
Mmattjwood 2026-10-16 github

Proton: Experimental experimental-11.0-20261014. Any game; seen with Risk of Rain 2 (632360). Linux Mint 22.3, Steam stable.

Steps: launch any game once, then Properties → Installed Files → Move install folder to another library.

Result: the move rolls back with "content file locked". content_log.txt:
canceled moving : File locked ... (Can't overwrite existing file ".../compatdata/632360/pfx/drive_c/windows/system32/DriverStore/FileRepository/igd_faux.inf_1/igd10iumd64.dll")

Cause: every prefix ends up with two copies of the same folder that differ only in case:

  • system32/driverstore/filerepository/igd_faux.inf_1/: made by Wine during prefix setup (igd10iumd64.dll link, igdext64.dll), next to input.inf_1, winebus.inf_1 etc.
  • system32/DriverStore/FileRepository/igd_faux.inf_1/: made by the launcher (proton line 1258, intc_store = "drive_c/windows/system32/DriverStore/FileRepository/igd_faux.inf_1"), which copies igdext64.dll into it again on every launch.

Steam's mover appears to compare names without regard to case, so the second copy collides with the first. Moving the prefix out of the way made the move succeed; steam-for-linux#12139 reports that deleting the file also works. Proton recreates the folder at every launch, so it comes back.

Suggested fix: use Wine's lowercase path in the launcher:

-                intc_store = "drive_c/windows/system32/DriverStore/FileRepository/igd_faux.inf_1"
+                intc_store = "drive_c/windows/system32/driverstore/filerepository/igd_faux.inf_1"

Prefixes that already have the mixed-case folder would also need it removed.

Related: ValveSoftware/steam-for-linux#12139 (same error, this file reported 2026-09-14), #10115 (added the copy).

Investigated with help from an AI assistant (Claude); the logs and testing are from my machine.

EErenYeager1836 2026-10-17 github

Confirmed this behavior on experimental_11.0. intc_store was introducing the mixed-case path DriverStore/FileRepository in proton, which conflicted with Wine's lowercase driverstore/filerepository on case-sensitive filesystems and broke Steam's case-insensitive file mover.

Submitted PR #10276 which standardizes intc_store to Wine's lowercase path and cleans up any legacy mixed-case DriverStore folder from existing prefixes so Steam's 'Move install folder' succeeds without requiring manual prefix deletion.

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