WebKitWebProcess CPU loop + memory leak (106-107% CPU sustained) on Linux/Wayland during browsing/search

[SafetyAdrien]

Please confirm the following.

• I checked the existing issues for duplicate problems
• I have tried resolving the issue using the support portal
• I have ensured my Modrinth App installation is up to date

What version of the Modrinth App are you using?

Modrinth App 0.18.0

What operating systems are you seeing the problem on?

No response

Describe the bug

Description

The Modrinth App's WebKitWebProcess enters a sustained CPU loop (100%+ CPU usage) combined with a continuous memory leak while browsing/searching mods or scrolling through the library. This happens on both the Flatpak and AUR (native) versions of the app.

Environment

• OS: CachyOS (Arch-based)
• Kernel: Wayland session, KDE Plasma
• GPU: NVIDIA RTX 3050/5060 (hybrid Nvidia/Intel laptop)
• App versions tested: Flatpak (com.modrinth.ModrinthApp) and AUR (modrinth-app)

Steps to reproduce

1. Launch Modrinth App
2. Go to search/discover mods
3. Type a search query and scroll through results
4. Observe CPU usage of the WebKitWebProcess in htop/ps

Observed behavior

Captured via ps aux --sort=-%cpu every second for 15s during normal browsing:

Steps to reproduce

1. Go to 'Discover'
2. Click on the search bar and type a mod name
3. Scroll down through the search results while typing
4. Observe CPU usage of WebKitWebProcess spike to 100%+ and stay pinned there

Expected behavior

CPU usage should remain low and stable while browsing/searching mods, similar to what happens when forcing GDK_BACKEND=x11 (which drops CPU to 1-3%).

Additional context

Workaround: launching with GDK_BACKEND=x11 modrinth-app completely resolves the issue — CPU stays at 1-3% during the same actions. This suggests the bug is specific to the native Wayland rendering path in WebKitGTK, not present under XWayland.

Detailed ps/htop capture logs available on request, showing WebKitWebProcess sustained at 106-107% CPU with continuously growing RES memory (4.6GB → 5.4GB) over a 15-second browsing session.

[huhuhuhuheh]

#3057