tui: Bun 1.4.2 segfault ~5s after idle startup on Linux x64 (v2.0.26) #54228

Summary

The TUI process crashes with a native Bun runtime segmentation fault ~5 seconds after startup on Linux x64, while completely idle (no user input). The background opencode serve --service process is unaffected. opencode 2.0.26 with the bundled Bun 1.4.2 runtime.

Environment

• opencode version: 2.0.26 (channel: latest)
• OS: Ubuntu Linux 6.8.0-146-generic x86_64
• Terminal: TERM=xterm-256color
• Shell: /bin/bash
• Install/channel: official installer, ~/.opencode/bin/opencode (standalone Bun executable, 201 MB ELF, not stripped)
• Active plugins: 12 plugins, including superpowers@git+https://github.com/obra/superpowers.git; MCP servers: chrome-devtools (30 tools, 2 connections)

Reproduction

1. Have opencode 2.0.26 on Linux x64 with the background service (opencode serve --service) running for >24h.
2. Launch opencode (TUI) in a project directory.
3. Do nothing.
4. ~5 seconds after startup the TUI dies.

Expected Behavior

The TUI stays running.

Actual Behavior

panic(main thread): Segmentation fault at address 0x2C000A00008
oh no: Bun has crashed. This indicates a bug in Bun, not your code.

To send a redacted crash report to Bun's team,
please file a GitHub issue using the link below:

 https://bun.report/1.4.2/la1744846fEsgggC+smh0B_yv13vB_i903vBmz93vBi903vBmz93vBi903vBmz93vBi903vBmz93vBi903vBi903vBmz93vBi903vBmz93vByv13vBms1vvB0yu+zBA2gsBwgggU

Segmentation fault (core dumped)

Additional Context

Server-side log timeline (from ~/.local/share/opencode/log/opencode.log), timestamps local:

• background service had been up since the previous day (unaffected, still running after the crash)
• 09:52:19 TUI client starts: plugin reconciliation (12 plugins), chrome-devtools MCP connects (30 tools x2), git detection for the project — all normal, no errors
• 09:52:24 the TUI's /api/event long-poll drops with InterruptError: All fibers interrupted — this is the crash moment, ~5s after launch
• 09:58 relaunching opencode works fine (this session has been stable since)

Other observations:

• No core dump was captured: Ubuntu apport ignores unpackaged binaries, and ~/.opencode/bin/opencode is not package-installed. The bun.report link above contains the redacted trace.
• Local opencode.db is heavily bloated: 19.4 GB total, 94% of pages on the freelist (page_count=4943277, freelist_count=4633098, page_size=4096; ~42k messages / ~173k parts). Probably unrelated to the crash, but noting it since TUI startup loads session data through the server.
• Memory was not constrained: 31 GB RAM total, ~28 GB available at the time.
• Frequency: third occurrence overall (twice before today); every time the relaunched session has been stable. Not reproducible on demand.
• The background service also appears to crash independently: the log shows background service starting reason=missing entries (2026-10-09), i.e. the service vanished and was auto-relaunched by a client, matching the pattern in server: v2.0.11 background service segfaults repeatedly (SIGSEGV, Linux x64) #50246. The serve PID also silently changed once during use today.
• Possibly related existing issues: tui: Linux x64 segfault in bundled Bun 1.4.2 (FFI stack), OpenCode 2.0.22 #53214 (bundled Bun 1.4.2 segfault, Linux TUI), serve: Bun 1.4.2 segfault (address 0x3D8) after long uptime on Windows #53688 (Bun 1.4.2 segfault after long uptime, Windows serve), server: v2.0.11 background service segfaults repeatedly (SIGSEGV, Linux x64) #50246 (repeated background service segfaults, Linux x64). This report adds a v2.0.26 / Linux TUI / crash-5s-after-startup data point with the bun.report link.