Merge 09c4fcfbed1d52857a4c90fade31f18058f5bf9b into 6b70c40f151ca051d403453bf019e1707b33bd5b

Fixes #3447

README.md

@@ -100,6 +100,8 @@ nvm is a version manager for [node.js](https://nodejs.org/en/), designed to be i
 
 ### Install & Update Script
 
+**If you use macOS, you must install Xcode and agree to the Xcode License before you install nvm.**
+
 To **install** or **update** nvm, you should run the [install script][2]. To do that, you may either download and run the script manually, or use the following cURL or Wget command:
 ```sh
 curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.40.1/install.sh | bash
@@ -108,7 +110,7 @@ curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.40.1/install.sh | bash
 wget -qO- https://raw.githubusercontent.com/nvm-sh/nvm/v0.40.1/install.sh | bash
 ```
 
-Running either of the above commands downloads a script and runs it. The script clones the nvm repository to `~/.nvm`, and attempts to add the source lines from the snippet below to the correct profile file (`~/.bash_profile`, `~/.zshrc`, `~/.profile`, or `~/.bashrc`).
+Running either of the above commands downloads a script and runs it. The script clones the nvm repository to `~/.nvm`, and attempts to add the source lines from the snippet below to the correct profile file (`~/.bash_profile`, `~/.zshrc`, `~/.profile`, or `~/.bashrc`). **If you don't have a profile file in your home dir, you'll need to add the appropriate one before you run the script.**
 
 <a id="profile_snippet"></a>
 ```sh

nvm.sh

@@ -196,6 +196,9 @@ nvm_install_latest_npm() {
   nvm_echo 'Attempting to upgrade to the latest working version of npm...'
   local NODE_VERSION
   NODE_VERSION="$(nvm_strip_iojs_prefix "$(nvm_ls_current)")"
+  local NPM_VERSION
+  NPM_VERSION="$(npm --version 2>/dev/null)"
+
   if [ "${NODE_VERSION}" = 'system' ]; then
     NODE_VERSION="$(node --version)"
   elif [ "${NODE_VERSION}" = 'none' ]; then
@@ -206,8 +209,6 @@ nvm_install_latest_npm() {
     nvm_err 'Unable to obtain node version.'
     return 1
   fi
-  local NPM_VERSION
-  NPM_VERSION="$(npm --version 2>/dev/null)"
   if [ -z "${NPM_VERSION}" ]; then
     nvm_err 'Unable to obtain npm version.'
     return 2