fix(doctor): add install checks for various nvm edge cases

closes TryGhost#281
- skip directory check if `--no-setup-linux-user` option is passed
- throw error if npm bin directory is not the same as the one used to install ghost-cli

lib/commands/doctor/checks/install.js

@@ -1,5 +1,5 @@
 'use strict';
-const fs = require('fs');
+const fs = require('fs-extra');
 const os = require('os');
 const eol = require('os').EOL;
 const path = require('path');
@@ -13,28 +13,39 @@ const isRoot = require('path-is-root');
 const errors = require('../../../errors');
 const cliPackage = require('../../../../package');
 
-function checkDirectoryAndAbove(dir) {
+function checkDirectoryAndAbove(dir, extra) {
     if (isRoot(dir)) {
         return;
     }
 
-    let stats = fs.lstatSync(dir);
-    let mode = new Mode(stats);
+    return fs.lstat(dir).then((stats) => {
+        let mode = new Mode(stats);
 
-    if (!mode.others.read) {
-        throw new errors.SystemError(
-            `The path ${dir} is not readable by other users on the system.${eol}` +
-            'This can cause issues with the CLI, please either make this directory ' +
-            'readable by others or install in another location.'
-        );
-    }
+        if (!mode.others.read) {
+            return Promise.reject(new errors.SystemError(
+                `The path ${dir} is not readable by other users on the system.${eol}` +
+                'This can cause issues with the CLI, please either make this directory ' +
+                `readable by others or ${extra} in another location.`
+            ));
+        }
 
-    return checkDirectoryAndAbove(path.join(dir, '../'));
+        return checkDirectoryAndAbove(path.join(dir, '../'), extra);
+    });
 }
 
 module.exports = [{
     title: 'Checking system Node.js version',
-    task: () => {
+    task: (ctx) => {
+        let globalBin = execa.shellSync('npm bin -g').stdout;
+
+        if (!process.argv[1].startsWith(globalBin)) {
+            return Promise.reject(new errors.SystemError(
+                `The version of Ghost-CLI you are running was not installed with this version of Node.${eol}` +
+                `This means there are likely two versions of Node running on your system,${eol} please ensure` +
+                'that you are only running one global version of Node before continuing.'
+            ));
+        }
+
         if (process.env.GHOST_NODE_VERSION_CHECK !== 'false' &&
             !semver.satisfies(process.versions.node, cliPackage.engines.node)) {
             return Promise.reject(new errors.SystemError(
@@ -45,6 +56,12 @@ module.exports = [{
                 'for more information'
             ));
         }
+
+        if (ctx.local || os.platform() !== 'linux' || (ctx.argv && ctx.argv['setup-linux-user'] === false)) {
+            return;
+        }
+
+        return checkDirectoryAndAbove(process.argv[0], 'install node and Ghost-CLI');
     }
 }, {
     title: 'Checking current folder permissions',
@@ -58,11 +75,11 @@ module.exports = [{
             ));
         }
 
-        if (ctx.local || os.platform() !== 'linux') {
+        if (ctx.local || os.platform() !== 'linux' || (ctx.argv && ctx.argv['setup-linux-user'] === false)) {
             return;
         }
 
-        checkDirectoryAndAbove(process.cwd());
+        return checkDirectoryAndAbove(process.cwd(), 'run `ghost install`');
     }
 }, {
     title: 'Checking operating system',