[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 ef7fc2f2c0 / #3212.
Fixes #3616.

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}"

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

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

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