test(e2e): a page load the machine had no buffer for is tried again

net::ERR_NO_BUFFER_SPACE stopped a release at its first page with nothing else running, and the
unchanged rerun passed. Every page load of the suite now goes through one helper, held by a test.

frontend/e2e/retryConnect.ts

@@ -11,6 +11,19 @@ const METHODS = new Set(["get", "post", "put", "patch", "delete", "head", "fetch
 const NO_CONNECTION = /\bconnect ETIMEDOUT\b/;
 const WAITS_MS = [500, 1000, 2000, 4000, 8000];
 
+/** `attempt` again after each wait while it fails with `transient`; any other failure goes on. */
+async function tryAgain<R>(attempt: () => Promise<R>, transient: RegExp): Promise<R> {
+  for (let i = 0; ; i++) {
+    try {
+      return await attempt();
+    } catch (e) {
+      const wait = WAITS_MS[i];
+      if (wait === undefined || !transient.test(String((e as Error)?.message))) throw e;
+      await new Promise((r) => setTimeout(r, wait));
+    }
+  }
+}
+
 /** `ctx` with its request methods trying a connect that timed out again (see above). */
 export function retryConnect<T extends object>(ctx: T): T {
   return new Proxy(ctx, {
@@ -18,17 +31,19 @@ export function retryConnect<T extends object>(ctx: T): T {
       const v: unknown = Reflect.get(target, key, target);
       if (typeof v !== "function") return v;
       if (typeof key !== "string" || !METHODS.has(key)) return v.bind(target);
-      return async (...args: unknown[]) => {
-        for (let i = 0; ; i++) {
-          try {
-            return await v.apply(target, args);
-          } catch (e) {
-            const wait = WAITS_MS[i];
-            if (wait === undefined || !NO_CONNECTION.test(String((e as Error)?.message))) throw e;
-            await new Promise((r) => setTimeout(r, wait));
-          }
-        }
-      };
+      return (...args: unknown[]) =>
+        tryAgain(() => Promise.resolve(v.apply(target, args)), NO_CONNECTION);
     },
   });
 }
+
+// A page load has a failure of its own on the same machine: `net::ERR_NO_BUFFER_SPACE`, the socket
+// call refused for the moment. It stopped a release's e2e at its first page (0.116.3, with nothing
+// else running; 0.107.3 aborted on it too), and the unchanged rerun passed. A browser does not try
+// a main document again by itself, and the request never left, so this does. The suite's every page
+// load goes through here (`e2eRetryConnect.test.ts`).
+const NO_BUFFER = /\bERR_NO_BUFFER_SPACE\b/;
+
+export function gotoRetrying<R>(page: { goto(url: string): Promise<R> }, url: string): Promise<R> {
+  return tryAgain(() => page.goto(url), NO_BUFFER);
+}