Crash when using Claude Code and hit cmd + d

[mikaelweiss]

Issue Description

844c07c0-7128-4606-1c56-ef5aba4d1ac5.ghosttycrash

Issue: Sometimes when I'm using Claude code, if I hit cmd + d to make a split, then ghostty crashes.
Notes: If I open ghostty, go to that directory, and resume the conversation with claude -r, and then hit cmd + d again, it'll crash again for that conversation. If I open a new tab, same directory, and hit cmd + d, then it won't crash.

I'm not sure what it is about the contents of that Claude Code conversation, but something about it makes the app crash

Expected Behavior

App doesn't crash

Actual Behavior

App crashes

Reproduction Steps

I can reproduce it with specific claude code conversations like I said earlier, but I have no insights about what specifically in that conversation makes it crash. I tried replicating the conversation in another Claude Code session, but didn't have the same issue with the app crashing.

Ghostty Logs

Filtering the log data using "subsystem == "com.mitchellh.ghostty""
Timestamp                       Thread     Type        Activity             PID    TTL  
2026-01-15 22:29:44.793129-0700 0x2fe834   Info        0x0                  73510  0    ghostty: [com.mitchellh.ghostty:io_exec] pty fd closed, read thread exiting
2026-01-15 22:29:44.808672-0700 0x2eb899   Info        0x0                  73510  0    ghostty: [com.mitchellh.ghostty:surface] surface closed addr=c7cc64000
2026-01-15 22:29:47.474415-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: d
2026-01-15 22:29:47.474451-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: a
2026-01-15 22:29:47.474473-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: d
2026-01-15 22:29:47.474479-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: a
2026-01-15 22:29:47.474487-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: d
2026-01-15 22:29:47.474491-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: a
2026-01-15 22:29:47.474551-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: d
2026-01-15 22:29:47.474557-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: a
2026-01-15 22:29:47.474603-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: d
2026-01-15 22:29:47.474649-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: a
2026-01-15 22:29:47.474687-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: d
2026-01-15 22:29:47.474717-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: a
2026-01-15 22:29:48.977495-0700 0x2eb899   Info        0x0                  73510  0    ghostty: [com.mitchellh.ghostty:ghostty] known but unimplemented action action=37
2026-01-15 22:29:48.980340-0700 0x2eb899   Info        0x0                  73510  0    ghostty: [com.mitchellh.ghostty:io_exec] found Ghostty resources dir: /Applications/Ghostty.app/Contents/Resources/ghostty
2026-01-15 22:29:48.980439-0700 0x2eb899   Info        0x0                  73510  0    ghostty: [com.mitchellh.ghostty:io_exec] shell integration automatically injected shell=termio.shell_integration.Shell.zsh
2026-01-15 22:29:48.980731-0700 0x2eb899   Info        0x0                  73510  0    ghostty: [com.mitchellh.ghostty:ghostty] known but unimplemented action action=20
2026-01-15 22:29:48.989548-0700 0x2fed78   Info        0x0                  73510  0    ghostty: [com.mitchellh.ghostty:io_exec] started subcommand path=/usr/bin/login pid=27414
2026-01-15 22:29:49.001382-0700 0x2eb8b7   Info        0x0                  73510  0    ghostty: [com.mitchellh.ghostty:page_list] adjusting page capacity=terminal.page.Capacity{ .cols = 89, .rows = 541, .styles = 128, .hyperlink_bytes = 1024, .grapheme_bytes = 8192, .string_bytes = 4096 }
2026-01-15 22:29:49.001841-0700 0x2eb8b7   Info        0x0                  73510  0    ghostty: [com.mitchellh.ghostty:page_list] adjusting page capacity=terminal.page.Capacity{ .cols = 89, .rows = 541, .styles = 128, .hyperlink_bytes = 1024, .grapheme_bytes = 8192, .string_bytes = 4096 }
2026-01-15 22:29:49.002224-0700 0x2eb8b7   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:io_thread] error during resize err=error.HyperlinkMapOutOfMemory
2026-01-15 22:29:49.004428-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: d
2026-01-15 22:29:49.004443-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: a
2026-01-15 22:29:49.004462-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: d
2026-01-15 22:29:49.004468-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: a
2026-01-15 22:29:49.004476-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: d
2026-01-15 22:29:49.004479-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: a
2026-01-15 22:29:49.004488-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: d
2026-01-15 22:29:49.004493-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: a
2026-01-15 22:29:49.004538-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: d
2026-01-15 22:29:49.004559-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: a
2026-01-15 22:29:49.004597-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: d
2026-01-15 22:29:49.004608-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: a
2026-01-15 22:29:49.013820-0700 0x2eb899   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:surface] failed to get pin for clicked point
2026-01-15 22:29:49.018607-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: d
2026-01-15 22:29:49.018624-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: a
2026-01-15 22:29:49.018637-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: d
2026-01-15 22:29:49.018641-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: a
2026-01-15 22:29:49.018646-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: d
2026-01-15 22:29:49.018649-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: a
2026-01-15 22:29:49.018657-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: d
2026-01-15 22:29:49.018660-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: a
2026-01-15 22:29:49.018747-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: d
2026-01-15 22:29:49.018823-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: a
2026-01-15 22:29:49.018847-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: d
2026-01-15 22:29:49.018865-0700 0x2eb8ba   Error       0x0                  73510  0    ghostty: [com.mitchellh.ghostty:stream] unimplemented execute: a

Ghostty Version

Ghostty 1.2.3

Version
  - version: 1.2.3
  - channel: stable
Build Config
  - Zig version   : 0.14.1
  - build mode    : builtin.OptimizeMode.ReleaseFast
  - app runtime   : apprt.Runtime.none
  - font engine   : font.main.Backend.coretext
  - renderer      : renderer.generic.Renderer(renderer.Metal)
  - libxev        : kqueue

OS Version Information

macOS 26.3 Beta (25D5087f)

(Linux only) Display Server

None

(Linux only) Desktop Environment/Window Manager

No response

Minimal Ghostty Configuration

# I don't think this is related, but this is the only config I have
keybind = shift+enter=text:\n

Additional Relevant Configuration

No response

I acknowledge that:

• I have reviewed the FAQ and confirm that my issue is NOT among them.
• I have searched the Ghostty repository (both open and closed Discussions and Issues) and confirm this is not a duplicate of an existing issue or discussion.
• I have checked the "Preview" tab on all text fields to ensure that everything looks right, and have wrapped all configuration and code in code blocks with a group of three backticks (```) on separate lines.

[keithce]

I'm seeing a similar issue but haven't traced it back to CMD + D.

The macOS logs are being spammed with:
2026-01-16 13:13:00.039631-0500 localhost ghostty[558]: [com.mitchellh.ghostty:stream] unimplemented execute: d
2026-01-16 13:13:00.039638-0500 localhost ghostty[558]: [com.mitchellh.ghostty:stream] unimplemented execute: a
2026-01-16 13:13:00.039667-0500 localhost ghostty[558]: [com.mitchellh.ghostty:stream] unimplemented execute: d
2026-01-16 13:13:00.039667-0500 localhost ghostty[558]: [com.mitchellh.ghostty:stream] unimplemented execute: a
2026-01-16 13:13:00.039668-0500 localhost ghostty[558]: [com.mitchellh.ghostty:stream] unimplemented execute: d
2026-01-16 13:13:00.039669-0500 localhost ghostty[558]: [com.mitchellh.ghostty:stream] unimplemented execute: a
2026-01-16 13:13:00.039738-0500 localhost ghostty[558]: [com.mitchellh.ghostty:stream] unimplemented execute: d

I'm on macOS version 14.7.6 (23H626)

This has only started happening in the last two days and it is within Claude Code.

It ends up leaving the claude process orphaned and I have to manually kill it. I didn't realize this until I did an 'ps' and found about 15 instances.

[mikaelweiss]

Whoa. Thanks for the heads up. I didn't realize it was orphaning the processes. Apparently I have 39 Claude code instances running right now! 🤦‍♂️

[paskal]

I think what you see is similar to #10338 I reported, can you reproduce it in tip version? auto-update-channel = tip in the settings of ghostty will bring it to you.

[mitchellh]

As noted in #10338, this should be resolved on tip. We just shipped a major change that makes it so that resize can now only crash/fail for system out of memory (which, we've never seen happen in practice for any desktop).