Add input manifest-file (#454)

Adds capability to maintain custom uv builds or to override the default
sources

src/utils/fetch.ts

@@ -0,0 +1,21 @@
+import { fetch as undiciFetch, ProxyAgent, type RequestInit } from "undici";
+
+export function getProxyAgent() {
+  const httpProxy = process.env.HTTP_PROXY || process.env.http_proxy;
+  if (httpProxy) {
+    return new ProxyAgent(httpProxy);
+  }
+
+  const httpsProxy = process.env.HTTPS_PROXY || process.env.https_proxy;
+  if (httpsProxy) {
+    return new ProxyAgent(httpsProxy);
+  }
+
+  return undefined;
+}
+
+export const fetch = async (url: string, opts: RequestInit) =>
+  await undiciFetch(url, {
+    dispatcher: getProxyAgent(),
+    ...opts,
+  });