diff --git a/lib/config.js b/lib/config.js
index 5f9819879be23..8873c38fa2a75 100644
--- a/lib/config.js
+++ b/lib/config.js
@@ -269,9 +269,13 @@ function list (cb) {
   var defKeys = getKeys(defaults)
   msg += '; default values\n'
   defKeys.forEach(function (k) {
-    if (defaults[k] && typeof defaults[k] === 'object') return
-    var val = JSON.stringify(defaults[k])
-    if (defaults[k] !== npm.config.get(k)) {
+    const def = defaults[k]
+    // XXX remove this skip when we stop putting log in the npm.config set.
+    if (def && typeof def === 'object' && !Array.isArray(def)) {
+      return
+    }
+    var val = JSON.stringify(def)
+    if (def !== npm.config.get(k)) {
       msg += '; ' + k + ' = ' + val + ' (overridden)\n'
     } else msg += k + ' = ' + val + '\n'
   })
diff --git a/lib/config/defaults.js b/lib/config/defaults.js
index c979dd0ce7ee9..8f3322099d35f 100644
--- a/lib/config/defaults.js
+++ b/lib/config/defaults.js
@@ -4,7 +4,6 @@ var path = require('path')
 var url = require('url')
 var Stream = require('stream').Stream
 var semver = require('semver')
-var stableFamily = semver.parse(process.version)
 var nopt = require('nopt')
 var os = require('os')
 var osenv = require('osenv')
@@ -68,9 +67,6 @@ nopt.invalidHandler = function (k, val, type) {
   }
 }
 
-if (!stableFamily || (+stableFamily.minor % 2)) stableFamily = null
-else stableFamily = stableFamily.major + '.' + stableFamily.minor
-
 var defaults
 
 var temp = osenv.tmpdir()
diff --git a/lib/config/flat-options.js b/lib/config/flat-options.js
index 6bde734ec4ef2..77913b8251dc4 100644
--- a/lib/config/flat-options.js
+++ b/lib/config/flat-options.js
@@ -159,7 +159,7 @@ const flatOptions = npm => npm.flatOptions || Object.freeze({
   packageLockOnly: npm.config.get('package-lock-only'),
   globalStyle: npm.config.get('global-style'),
   legacyBundling: npm.config.get('legacy-bundling'),
-  scriptShell: npm.config.get('script-shell'),
+  scriptShell: npm.config.get('script-shell') || undefined,
   omit: buildOmitList(npm),
 
   // used to build up the appropriate {add:{...}} options to Arborist.reify
diff --git a/lib/config/set-envs.js b/lib/config/set-envs.js
index faa75b5f58b10..63c6006f5bfb3 100644
--- a/lib/config/set-envs.js
+++ b/lib/config/set-envs.js
@@ -5,6 +5,9 @@
 
 const envName = name => `npm_config_${name.replace(/-/g, '_')}`
 
+// Return the env key if this is a thing that belongs in the env.
+// Ie, if the key isn't a @scope, //nerf.dart, or _private,
+// and the value is a string or array.  Otherwise return false.
 const envKey = (key, val) => {
   return !/^[\/@_]/.test(key) &&
     (typeof val === 'string' || Array.isArray(val)) &&
@@ -13,6 +16,22 @@ const envKey = (key, val) => {
 
 const envVal = val => Array.isArray(val) ? val.join('\n\n') : val
 
+const sameConfigValue = (def, val) =>
+  !Array.isArray(val) || !Array.isArray(def) ? def === val
+    : sameArrayValue(def, val)
+
+const sameArrayValue = (def, val) => {
+  if (def.length !== val.length) {
+    return false
+  }
+  for (let i = 0; i < def.length; i++) {
+    if (def[i] !== val[i]) {
+      return false
+    }
+  }
+  return true
+}
+
 const setEnvs = npm => {
   // The objects in the config.list array are arranged in
   // a prototype chain, so we can just for/in over the top
@@ -23,7 +42,7 @@ const setEnvs = npm => {
   for (const key in configs) {
     const val = configs[key]
     const environ = envKey(key, val)
-    if (defaults[key] !== val && environ) {
+    if (!sameConfigValue(defaults[key], val) && environ) {
       process.env[environ] = envVal(val)
     }
   }