From df3816399981e20dc78cc55e5a32a7c2fd1dd57c Mon Sep 17 00:00:00 2001
From: Noah Masur <7386960+nmasur@users.noreply.github.com>
Date: Mon, 3 Aug 2026 15:39:17 -0400
Subject: [PATCH] fix: cap zellij session name length to avoid socket path
 overflow crash

---
 docs/CHANGELOG.md                                 | 15 ++++++++++++++-
 .../modules/nmasur/presets/programs/zellij.nix    |  9 ++++++++-
 2 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index 822f7e8a..3174e152 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -1,9 +1,22 @@
 # Changelog
 
+## 2026-08-03
+
+- Fixed the `zellij-session` fish function in `presets/programs/zellij.nix`
+  truncating the session name (derived from the target directory basename)
+  to 20 characters. Zellij names each session's Unix-domain IPC socket
+  `$TMPDIR/zellij-<uid>/<version>/<name>`, and on macOS the socket path is
+  capped at 103 bytes. The `/var/folders/...` `$TMPDIR` prefix consumes ~79
+  of those, leaving only ~24 chars for the name, so switching into directories
+  with long basenames overflowed the socket path. Because `switch-session`
+  had already detached from the current session by the time the new one failed
+  to bind, the failure took down the entire terminal instead of erroring
+  gracefully.
+
 ## 2026-07-25
 
 - Added jjui config generation to `jujutsu.nix` in Home Manager to include custom GitHub ruleset bypass commands (`ctrl+b` and `ctrl+shift+b`).
-- Added `overlays/cheetah3.nix` to disable `pythonMetadataCheckPhase` for `cheetah3`. 
+- Added `overlays/cheetah3.nix` to disable `pythonMetadataCheckPhase` for `cheetah3`.
   This fixes an issue where the NixOS rebuild fails for `sabnzbd` due to `importlib.metadata.PackageNotFoundError: No package metadata was found for cheetah3` during the Python package evaluation in `nixos-unstable`.
 
 ## 2026-07-20
diff --git a/platforms/home-manager/modules/nmasur/presets/programs/zellij.nix b/platforms/home-manager/modules/nmasur/presets/programs/zellij.nix
index b0c91da2..762c40eb 100644
--- a/platforms/home-manager/modules/nmasur/presets/programs/zellij.nix
+++ b/platforms/home-manager/modules/nmasur/presets/programs/zellij.nix
@@ -58,8 +58,15 @@ in
               if test "$TARGET_DIR" = $(pwd)
                 return 1
               end
+              # Zellij names each session's IPC socket $TMPDIR/zellij-<uid>/<ver>/<name>.
+              # On macOS the socket path is capped at 103 bytes; the $TMPDIR prefix under
+              # /var/folders/... eats ~79 of those, leaving only ~24 chars for the name.
+              # A longer basename overflows the socket path, and because switch-session has
+              # already detached from the current session by the time the new one fails to
+              # bind, it takes the whole terminal down. Truncate to stay well under the limit.
+              set SESSION_NAME (basename $TARGET_DIR | string sub --length 20)
               echo "$ZELLIJ_SESSION_NAME" > ~/.local/state/zellij-last-session
-              ${lib.getExe pkgs.zellij} action switch-session $(basename $TARGET_DIR) --cwd $TARGET_DIR --layout default
+              ${lib.getExe pkgs.zellij} action switch-session $SESSION_NAME --cwd $TARGET_DIR --layout default
             '';
         };
         gh-run = {