From f1e7a84cb51ec41eac0e6bb7164662c66332fc34 Mon Sep 17 00:00:00 2001
From: Jordan Harband <ljharb@gmail.com>
Date: Tue, 14 Jul 2026 23:16:39 -0700
Subject: [PATCH] [Robustness] avoid a `set -u` error when `$_` is unset

Sourcing nvm.sh under `set -u` on a POSIX shell that leaves `$_` unset (e.g. busybox ash or dash on Alpine, where the parent shell does not export it) aborted at `NVM_SCRIPT_SOURCE="$_"`.
Default to empty; the only consumer already falls back to `$0`.
---
 nvm.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/nvm.sh b/nvm.sh
index 3559058b..d57d0079 100755
--- a/nvm.sh
+++ b/nvm.sh
@@ -11,7 +11,7 @@
 { # this ensures the entire script is downloaded #
 
 # shellcheck disable=SC3028
-NVM_SCRIPT_SOURCE="$_"
+NVM_SCRIPT_SOURCE="${_:-}"
 
 nvm_is_zsh() {
   [ -n "${ZSH_VERSION-}" ]