From 39e71eab492fa882782c8f59a2efbb27d9b839b5 Mon Sep 17 00:00:00 2001
From: Jordan Harband <ljharb@gmail.com>
Date: Sat, 14 Mar 2026 12:53:14 -0700
Subject: [PATCH] [Fix] `nvm_get_arch`: only apply musl suffix on x64 Alpine

Alpine detection unconditionally set `x64-musl` regardless of actual architecture, which would be incorrect on ARM-based Alpine containers.

Bug introduced in https://github.com/nvm-sh/nvm/commit/ef7fc2f2c06ad75fe7fbabf28d427561ae7b007d / #3212.
Fixes #3616.
---
 nvm.sh                                   |  5 ++-
 test/fast/Unit tests/nvm_get_arch alpine | 48 ++++++++++++++++++++++++
 test/mocks/uname_linux_aarch64           |  5 +++
 test/mocks/uname_linux_x86_64            |  5 +++
 4 files changed, 62 insertions(+), 1 deletion(-)
 create mode 100755 test/fast/Unit tests/nvm_get_arch alpine
 create mode 100755 test/mocks/uname_linux_aarch64
 create mode 100755 test/mocks/uname_linux_x86_64

diff --git a/nvm.sh b/nvm.sh
index a59ec6d..d853c9d 100755
--- a/nvm.sh
+++ b/nvm.sh
@@ -2171,7 +2171,10 @@ nvm_get_arch() {
   fi
 
   if [ -f "/etc/alpine-release" ]; then
-    NVM_ARCH=x64-musl
+    # Alpine Linux uses musl libc; only x64-musl binaries are available
+    case "${NVM_ARCH}" in
+      x64) NVM_ARCH=x64-musl ;;
+    esac
   fi
 
   nvm_echo "${NVM_ARCH}"
diff --git a/test/fast/Unit tests/nvm_get_arch alpine b/test/fast/Unit tests/nvm_get_arch alpine
new file mode 100755
index 0000000..560a89a
--- /dev/null
+++ b/test/fast/Unit tests/nvm_get_arch alpine	
@@ -0,0 +1,48 @@
+#!/bin/sh
+
+ORIG_PATH="${PATH}"
+
+cleanup() {
+  rm -f ./uname
+  export PATH="${ORIG_PATH}"
+}
+
+die () { cleanup; echo "$@" ; exit 1; }
+
+: nvm.sh
+\. ../../../nvm.sh
+
+MOCKS_DIR="$(pwd)/../../mocks"
+export PATH=".:${PATH}"
+
+# On Alpine (where /etc/alpine-release exists), x64 should get -musl suffix
+# and arm64 should NOT get -musl suffix.
+# On non-Alpine, neither should get -musl.
+
+if [ -f "/etc/alpine-release" ]; then
+  # x64 on Alpine should produce x64-musl
+  ln -sf "${MOCKS_DIR}/uname_linux_x86_64" ./uname
+  OUTPUT="$(nvm_get_arch)"
+  rm -f ./uname
+  [ "_${OUTPUT}" = "_x64-musl" ] || die "x64 on Alpine should be x64-musl, got ${OUTPUT}"
+
+  # aarch64 on Alpine should produce arm64, NOT arm64-musl
+  ln -sf "${MOCKS_DIR}/uname_linux_aarch64" ./uname
+  OUTPUT="$(nvm_get_arch)"
+  rm -f ./uname
+  [ "_${OUTPUT}" = "_arm64" ] || die "aarch64 on Alpine should be arm64 (no musl suffix), got ${OUTPUT}"
+else
+  # x64 on non-Alpine should produce x64 (no musl suffix)
+  ln -sf "${MOCKS_DIR}/uname_linux_x86_64" ./uname
+  OUTPUT="$(nvm_get_arch)"
+  rm -f ./uname
+  [ "_${OUTPUT}" = "_x64" ] || die "x64 on non-Alpine should be x64, got ${OUTPUT}"
+
+  # aarch64 on non-Alpine should produce arm64
+  ln -sf "${MOCKS_DIR}/uname_linux_aarch64" ./uname
+  OUTPUT="$(nvm_get_arch)"
+  rm -f ./uname
+  [ "_${OUTPUT}" = "_arm64" ] || die "aarch64 on non-Alpine should be arm64, got ${OUTPUT}"
+fi
+
+cleanup
diff --git a/test/mocks/uname_linux_aarch64 b/test/mocks/uname_linux_aarch64
new file mode 100755
index 0000000..fc0c32d
--- /dev/null
+++ b/test/mocks/uname_linux_aarch64
@@ -0,0 +1,5 @@
+if [ "_$1" = "_-m" ]; then
+  echo "aarch64"
+else
+  echo "Linux hostname 5.15.0-1 #1 SMP aarch64 aarch64 aarch64 GNU/Linux"
+fi
diff --git a/test/mocks/uname_linux_x86_64 b/test/mocks/uname_linux_x86_64
new file mode 100755
index 0000000..ce40465
--- /dev/null
+++ b/test/mocks/uname_linux_x86_64
@@ -0,0 +1,5 @@
+if [ "_$1" = "_-m" ]; then
+  echo "x86_64"
+else
+  echo "Linux hostname 5.15.0-1 #1 SMP x86_64 x86_64 x86_64 GNU/Linux"
+fi