Tweak: read auth providers in-process on the sign-in page, set env earlier (#7023)

src/pages/auth/signin.jsx

@@ -1,5 +1,5 @@
 import classNames from "classnames";
-import { getProviders, signIn } from "next-auth/react";
+import { signIn } from "next-auth/react";
 import { useRouter } from "next/router";
 import { useEffect, useMemo, useState } from "react";
 import { BiShieldQuarter } from "react-icons/bi";
@@ -94,10 +94,8 @@ export default function SignIn({ providers, settings }) {
             <div className="mx-auto flex h-12 w-12 items-center justify-center rounded-2xl bg-theme-500/15 text-theme-600 dark:text-theme-300">
               <BiShieldQuarter className="h-6 w-6" />
             </div>
-            <h1 className="mt-6 text-2xl font-semibold text-gray-900 dark:text-slate-100">
-              Authentication not configured
-            </h1>
-            <p className="mt-3 text-sm text-gray-600 dark:text-slate-400">OIDC is disabled or misconfigured.</p>
+            <h1 className="mt-6 text-2xl font-semibold text-gray-900 dark:text-slate-100">Authentication error</h1>
+            <p className="mt-3 text-sm text-gray-600 dark:text-slate-400">Auth is disabled or misconfigured.</p>
           </div>
         </main>
       </>
@@ -202,7 +200,16 @@ export default function SignIn({ providers, settings }) {
 }
 
 export async function getServerSideProps(context) {
-  const providers = await getProviders();
+  // Avoid getProviders() fetch
+  let providers = {};
+  try {
+    // Dynamic so a bad config throws in here rather than at page load
+    const { authOptions } = await import("pages/api/auth/[...nextauth]");
+    providers = Object.fromEntries(authOptions.providers.map(({ id, name, type }) => [id, { id, name, type }]));
+  } catch (e) {
+    console.error("Unable to load auth providers: %s", e.message);
+  }
+
   const homepageSettings = getSettings();
   const settings = Object.fromEntries(
     PUBLIC_SIGN_IN_SETTINGS.filter((key) => Object.prototype.hasOwnProperty.call(homepageSettings, key)).map((key) => [