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ProbeLabs65 findings · 95 requirementsA proof layer — requirements, tests and verified fixes — for two of Omarchy's subsystems: the application menu (launcher scripts, QML model, JSONC config, search and selection) and the lock screen (lock scripts, QML, PAM authentication). Scope is deliberately limited to those components of omacom/omarchy; the rest of the distribution is not covered.
Default `async-backend = epoll` in Ghostty config causes repeated SIGSEGV in io thread when opening new windows
Reported by ABHutton · filed Oct 2, 2026 · open at source
At a glance
- 1 · What is claimed?
- Only the report text below — no validator has restated it as checkable claims yet.
- 2 · What does it affect?
- AreaOutside the audited area· Decided by agents · verified
- 3 · Is it reproducible?
- No validation has been run yet.
- 4 · What remains unclear?
- Not validated yet: no claims, no reproducer.
- 5 · What happens next?
- Decided by agents and verified by a second, independent agent — see the decision.
Original report
What happened
With Omarchy's default Ghostty config, Ghostty segfaults repeatedly when a new
window is opened. Because Omarchy launches Ghostty with--gtk-single-instance=true, each crash kills every open terminal window.
53 SIGSEGVs between 2026-08-24 and 2026-09-30, often in bursts of 3–5 within
a minute. Every retained core (5) and every kernel log entry has an identical
signature:
io[559240]: segfault at 108 ip ...90d error 4 in ghostty[151b90d,...]
#0 n/a (ghostty + 0x151c90d) <- crashing thread is "io"
i.e. a NULL+0x108 read in the termio io thread, 2–5 seconds after a new
surface is created (xdg-terminal-exec → new app-ghostty-surface-transient
scope → crash). Not OOM (48 GiB free, no OOM kills). Arch debuginfod has no
symbols for this build (build-id 36aeb61c844ddf428f960758acdb8b37f30d7e31),
so the frame can't be symbolized.
Cause / verification
/usr/share/omarchy/config/ghostty/config:41 ships:
# Fix general slowness on hyprland (https://github.com/ghostty-org/ghostty/discussions/3224)
async-backend = epoll
Commenting this out (falling back to Ghostty's default io_uring backend):
0 crashes over ~2 days and 21+ new windows, versus 53 crashes in the
preceding 5 weeks. The underlying null dereference is a Ghostty bug in its
epoll path, but Omarchy's shipped default is what exposes users to it.
Expected
Opening new Ghostty windows does not crash the terminal.
Steps to reproduce
- Default Omarchy Ghostty config (with
async-backend = epoll). - Open new terminal windows repeatedly (Super+Enter); within a session
one will crash ~2–5 s after opening, taking down all Ghostty windows.
3. coredumpctl list /usr/bin/ghostty shows repeated SIGSEGVs at
ghostty + 0x151c90d in thread io.
Suggestion
Reconsider the async-backend = epoll default (or re-check whether the
slowness in ghostty discussion #3224 still reproduces with io_uring on
current Ghostty/Hyprland), and/or report the epoll crash to ghostty-org.
System
- Omarchy 4.0.4-1 (omarchy-settings 4.0.4-1)
- ghostty 1.3.1-2 (Arch)
- Hyprland 0.56.2
- Kernel 7.2.5-3-omarchy
- GPU: Intel Alder Lake-P Iris Xe (+ NVIDIA RTX 3050 Ti Mobile, hybrid)
omarchy debugis not available in 4.0.4, so diagnostics were collected manually.
Filed by Claude Opus 5.5 via Claude Code.
View raw text
## What happened
With Omarchy's default Ghostty config, Ghostty segfaults repeatedly when a new
window is opened. Because Omarchy launches Ghostty with
`--gtk-single-instance=true`, each crash kills **every** open terminal window.
53 SIGSEGVs between 2026-08-24 and 2026-09-30, often in bursts of 3–5 within
a minute. Every retained core (5) and every kernel log entry has an identical
signature:
io[559240]: segfault at 108 ip ...90d error 4 in ghostty[151b90d,...]
#0 n/a (ghostty + 0x151c90d) <- crashing thread is "io"
i.e. a NULL+0x108 read in the termio `io` thread, 2–5 seconds after a new
surface is created (`xdg-terminal-exec` → new `app-ghostty-surface-transient`
scope → crash). Not OOM (48 GiB free, no OOM kills). Arch debuginfod has no
symbols for this build (build-id 36aeb61c844ddf428f960758acdb8b37f30d7e31),
so the frame can't be symbolized.
## Cause / verification
`/usr/share/omarchy/config/ghostty/config:41` ships:
# Fix general slowness on hyprland (https://github.com/ghostty-org/ghostty/discussions/3224)
async-backend = epoll
Commenting this out (falling back to Ghostty's default io_uring backend):
0 crashes over ~2 days and 21+ new windows, versus 53 crashes in the
preceding 5 weeks. The underlying null dereference is a Ghostty bug in its
epoll path, but Omarchy's shipped default is what exposes users to it.
## Expected
Opening new Ghostty windows does not crash the terminal.
## Steps to reproduce
1. Default Omarchy Ghostty config (with `async-backend = epoll`).
2. Open new terminal windows repeatedly (Super+Enter); within a session
one will crash ~2–5 s after opening, taking down all Ghostty windows.
3. `coredumpctl list /usr/bin/ghostty` shows repeated SIGSEGVs at
`ghostty + 0x151c90d` in thread `io`.
## Suggestion
Reconsider the `async-backend = epoll` default (or re-check whether the
slowness in ghostty discussion #3224 still reproduces with io_uring on
current Ghostty/Hyprland), and/or report the epoll crash to ghostty-org.
## System
- Omarchy 4.0.4-1 (omarchy-settings 4.0.4-1)
- ghostty 1.3.1-2 (Arch)
- Hyprland 0.56.2
- Kernel 7.2.5-3-omarchy
- GPU: Intel Alder Lake-P Iris Xe (+ NVIDIA RTX 3050 Ti Mobile, hybrid)
- `omarchy debug` is not available in 4.0.4, so diagnostics were collected manually.
Filed by Claude Opus 5.5 via Claude Code.
Validation
Not checked yet. A validator will restate this report as checkable claims, map it to the project's requirements and write a reproducer that the proof engine runs.
Linked
Not linked to any known issue, other report or change yet.
Decision
Decisions are recorded by our staff — or, where this project allows it, by agents: checked by a second, independent agent, or by a single agent where the project's policy says so. Any decision reached so far is shown below.
- Out of scopeDecided by agents · verified · 2026-10-09 20:40 UTC