From 4d4cdca2c853292306e944b8e814a536b992316b Mon Sep 17 00:00:00 2001
From: Alex Plotnick <alex@oxidecomputer.com>
Date: Sat, 15 Aug 2026 16:54:00 +0000
Subject: [PATCH] Fix a crash on ^C during a REPL command

Pressing ^C while a REPL command ran could crash the client with a
core dump. The crash came from a stale rustyline signal handler
writing to a closed pipe. Enabling rustyline's signal-hook feature
makes it share the signal registry that tokio uses, and no stale
handler remains installed.

Co-Authored-By: Claude Mythos 5 <noreply@anthropic.com>
---
 Cargo.lock | 11 +++++++++++
 Cargo.toml |  2 +-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/Cargo.lock b/Cargo.lock
index 18c1e75..8563b05 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4066,6 +4066,7 @@ dependencies = [
  "memchr",
  "nix",
  "radix_trie",
+ "signal-hook",
  "termios",
  "unicode-segmentation",
  "unicode-width 0.2.2",
@@ -4453,6 +4454,16 @@ version = "2.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f8fadd59c855ef2080decdef8ff161eb6661b86933c9d82e5ba29dc602a55aba"
 
+[[package]]
+name = "signal-hook"
+version = "0.3.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d881a16cf4426aa584979d30bd82cb33429027e42122b169753d6ef1085ed6e2"
+dependencies = [
+ "libc",
+ "signal-hook-registry",
+]
+
 [[package]]
 name = "signal-hook-registry"
 version = "1.4.8"
diff --git a/Cargo.toml b/Cargo.toml
index 8ff48fa..a3df96c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -48,7 +48,7 @@ rlimit = "0.10"
 rumors = { git = "https://github.com/oxidecomputer/rumors", rev = "b2675dbef99b784efb817db01920ee59dac708c3" }
 rustix = { version = "1", features = ["fs", "process", "pty", "termios"] }
 rustls = "0.23"
-rustyline = { version = "17", features = ["termios"] }
+rustyline = { version = "17", features = ["signal-hook", "termios"] }
 schemars = { version = "0.8", features = ["chrono"] }
 serde = "1"
 serde_json = "1"