install: say --network-concurrency defaults to 64 in help and docs

completions/bun-cli.json

@@ -427,7 +427,7 @@
         },
         {
           "name": "network-concurrency",
-          "description": "Maximum number of concurrent network requests (default 48)",
+          "description": "Maximum number of concurrent network requests (default 64)",
           "hasValue": true,
           "valueType": "val",
           "required": false,
@@ -748,7 +748,7 @@
         },
         {
           "name": "network-concurrency",
-          "description": "Maximum number of concurrent network requests (default 48)",
+          "description": "Maximum number of concurrent network requests (default 64)",
           "hasValue": true,
           "valueType": "val",
           "required": false,
@@ -1079,7 +1079,7 @@
         },
         {
           "name": "network-concurrency",
-          "description": "Maximum number of concurrent network requests (default 48)",
+          "description": "Maximum number of concurrent network requests (default 64)",
           "hasValue": true,
           "valueType": "val",
           "required": false,
@@ -1351,7 +1351,7 @@
         },
         {
           "name": "network-concurrency",
-          "description": "Maximum number of concurrent network requests (default 48)",
+          "description": "Maximum number of concurrent network requests (default 64)",
           "hasValue": true,
           "valueType": "val",
           "required": false,
@@ -1769,7 +1769,7 @@
         },
         {
           "name": "network-concurrency",
-          "description": "Maximum number of concurrent network requests (default 48)",
+          "description": "Maximum number of concurrent network requests (default 64)",
           "hasValue": true,
           "valueType": "val",
           "required": false,
@@ -2149,7 +2149,7 @@
         },
         {
           "name": "network-concurrency",
-          "description": "Maximum number of concurrent network requests (default 48)",
+          "description": "Maximum number of concurrent network requests (default 64)",
           "hasValue": true,
           "valueType": "val",
           "required": false,
@@ -2432,7 +2432,7 @@
         },
         {
           "name": "network-concurrency",
-          "description": "Maximum number of concurrent network requests (default 48)",
+          "description": "Maximum number of concurrent network requests (default 64)",
           "hasValue": true,
           "valueType": "val",
           "required": false,
@@ -2691,7 +2691,7 @@
         },
         {
           "name": "network-concurrency",
-          "description": "Maximum number of concurrent network requests (default 48)",
+          "description": "Maximum number of concurrent network requests (default 64)",
           "hasValue": true,
           "valueType": "val",
           "required": false,
@@ -2943,7 +2943,7 @@
         },
         {
           "name": "network-concurrency",
-          "description": "Maximum number of concurrent network requests (default 48)",
+          "description": "Maximum number of concurrent network requests (default 64)",
           "hasValue": true,
           "valueType": "val",
           "required": false,
@@ -3248,7 +3248,7 @@
         },
         {
           "name": "network-concurrency",
-          "description": "Maximum number of concurrent network requests (default 48)",
+          "description": "Maximum number of concurrent network requests (default 64)",
           "hasValue": true,
           "valueType": "val",
           "required": false,
@@ -3677,7 +3677,7 @@
         },
         {
           "name": "network-concurrency",
-          "description": "Maximum number of concurrent network requests (default 48)",
+          "description": "Maximum number of concurrent network requests (default 64)",
           "hasValue": true,
           "valueType": "val",
           "required": false,

docs/snippets/cli/add.mdx

@@ -115,7 +115,7 @@ bun add <package> <@version>
   variables
 </ParamField>
 
-<ParamField path="--network-concurrency" type="number" default="48">
+<ParamField path="--network-concurrency" type="number" default="64">
   Maximum number of concurrent network requests
 </ParamField>
 

docs/snippets/cli/install.mdx

@@ -156,7 +156,7 @@ bun install <name>@<version>
   Maximum number of concurrent jobs for lifecycle scripts (default: 2x CPU cores)
 </ParamField>
 
-<ParamField path="--network-concurrency" type="number" default="48">
+<ParamField path="--network-concurrency" type="number" default="64">
   Maximum number of concurrent network requests
 </ParamField>
 

docs/snippets/cli/link.mdx

@@ -92,7 +92,7 @@ bun link <packages>
   variables
 </ParamField>
 
-<ParamField path="--network-concurrency" type="number" default="48">
+<ParamField path="--network-concurrency" type="number" default="64">
   Maximum number of concurrent network requests
 </ParamField>
 

docs/snippets/cli/outdated.mdx

@@ -98,8 +98,8 @@ bun outdated <filter>
   Use a specific registry by default, overriding <code>.npmrc</code>, <code>bunfig.toml</code> and environment variables
 </ParamField>
 
-<ParamField path="--network-concurrency" type="number" default="48">
-  Maximum number of concurrent network requests (default 48)
+<ParamField path="--network-concurrency" type="number" default="64">
+  Maximum number of concurrent network requests (default 64)
 </ParamField>
 
 ### Caching

docs/snippets/cli/patch.mdx

@@ -100,8 +100,8 @@ bun patch <package>@<version>
   variables
 </ParamField>
 
-<ParamField path="--network-concurrency" type="number" default="48">
-  Maximum number of concurrent network requests (default 48)
+<ParamField path="--network-concurrency" type="number" default="64">
+  Maximum number of concurrent network requests (default 64)
 </ParamField>
 
 ### Performance &amp; Resource

docs/snippets/cli/publish.mdx

@@ -171,7 +171,7 @@ bun publish --cafile ./ca-cert.pem
   Platform optimizations: `clonefile` (default), `hardlink`, `symlink`, or `copyfile`
 </ParamField>
 
-<ParamField path="--network-concurrency" type="number" default="48">
+<ParamField path="--network-concurrency" type="number" default="64">
   Maximum concurrent network requests
 </ParamField>
 

docs/snippets/cli/remove.mdx

@@ -145,6 +145,6 @@ bun remove <package>
   <code>hardlink</code>, <code>symlink</code>, <code>copyfile</code>
 </ParamField>
 
-<ParamField path="--network-concurrency" type="number" default="48">
-  Maximum number of concurrent network requests (default 48)
+<ParamField path="--network-concurrency" type="number" default="64">
+  Maximum number of concurrent network requests (default 64)
 </ParamField>

docs/snippets/cli/update.mdx

@@ -78,8 +78,8 @@ bun up
   Use a specific registry by default, overriding <code>.npmrc</code>, <code>bunfig.toml</code> and environment variables
 </ParamField>
 
-<ParamField path="--network-concurrency" type="number" default="48">
-  Maximum number of concurrent network requests (default 48)
+<ParamField path="--network-concurrency" type="number" default="64">
+  Maximum number of concurrent network requests (default 64)
 </ParamField>
 
 ### Caching

src/install/PackageManager/CommandLineArguments.rs

@@ -50,6 +50,15 @@ const BACKEND_PARAM: ParamType = clap::param!(
     "--backend <STR>                       Platform-specific optimizations for installing dependencies. Possible values: \"hardlink\" (default), \"symlink\", \"copyfile\""
 );
 
+const NETWORK_CONCURRENCY_PARAM: ParamType = clap::param!(
+    "--network-concurrency <NUM>           Maximum number of concurrent network requests (default 64)"
+);
+const _: () = assert!(
+    super::DEFAULT_MAX_SIMULTANEOUS_REQUESTS_FOR_BUN_INSTALL == 64
+        && super::DEFAULT_MAX_SIMULTANEOUS_REQUESTS_FOR_BUN_INSTALL_FOR_PROXIES == 64,
+    "update the default in the --network-concurrency help text (and docs/snippets/cli/*.mdx)"
+);
+
 const SHARED_HEAD_PARAMS: &[ParamType] = &[
     clap::param!("-c, --config <STR>?                   Specify path to config file (bunfig.toml)"),
     clap::param!("-y, --yarn                            Write a yarn.lock file (yarn v1)"),
@@ -103,9 +112,7 @@ const SHARED_TAIL_PARAMS: &[ParamType] = &[
     clap::param!(
         "--concurrent-scripts <NUM>            Maximum number of concurrent jobs for lifecycle scripts (default: 2x CPU cores)"
     ),
-    clap::param!(
-        "--network-concurrency <NUM>           Maximum number of concurrent network requests (default 48)"
-    ),
+    NETWORK_CONCURRENCY_PARAM,
     clap::param!("--save-text-lockfile                  Save a text-based lockfile"),
     clap::param!(
         "--omit <dev|optional|peer>...         Exclude 'dev', 'optional', or 'peer' dependencies from install"

test/cli/install/bun-install.test.ts

@@ -67,6 +67,66 @@ async function withContext(
 // Default context options for most tests
 const defaultOpts = { linker: "hoisted" as const };
 
+// BUN_CONFIG_MAX_HTTP_REQUESTS is documented as another way to set the request
+// limit, so it must not leak in from the outer environment while measuring it.
+const networkConcurrencyEnv = { ...env, BUN_CONFIG_MAX_HTTP_REQUESTS: undefined };
+
+// Runs `bun install` with one dependency more than `limit`, against a registry
+// that holds every manifest request open, and asserts that bun has exactly
+// `limit` requests in flight: the extra dependency has to wait for a slot.
+async function expectInstallInFlightLimit(ctx: TestContext, limit: number) {
+  const dependencies: Record<string, string> = {};
+  for (let i = 0; i < limit + 1; i++) dependencies[`dep-${i}`] = "^1";
+  await writeFile(
+    join(ctx.package_dir, "package.json"),
+    JSON.stringify({ name: "foo", version: "0.0.1", dependencies }),
+  );
+
+  let inFlight = 0;
+  let maxInFlight = 0;
+  const limitReached = Promise.withResolvers<void>();
+  const limitExceeded = Promise.withResolvers<void>();
+  const release = Promise.withResolvers<void>();
+  setContextHandler(ctx, async () => {
+    inFlight++;
+    maxInFlight = Math.max(maxInFlight, inFlight);
+    if (inFlight >= limit) limitReached.resolve();
+    if (inFlight > limit) limitExceeded.resolve();
+    await release.promise;
+    inFlight--;
+    return new Response("404", { status: 404 });
+  });
+
+  await using proc = spawn({
+    cmd: [bunExe(), "install"],
+    cwd: ctx.package_dir,
+    stdout: "pipe",
+    stderr: "pipe",
+    stdin: "ignore",
+    env: networkConcurrencyEnv,
+  });
+  try {
+    // A real limit below `limit` parks bun (and this wait) with fewer requests
+    // in flight and no further signal, so the wait is bounded (generously: this
+    // is a debug build under CI load) and the assertions below report what was
+    // reached. proc.exited covers bun giving up early.
+    await Promise.race([limitReached.promise, proc.exited, Bun.sleep(30_000)]);
+    // bun sends everything its limit allows in one burst, so a request beyond
+    // the limit arrives right behind the others. That it never arrives can only
+    // be observed by giving it a moment to show up.
+    await Promise.race([limitExceeded.promise, Bun.sleep(500)]);
+  } finally {
+    release.resolve();
+  }
+  const [stdout, stderr, exitCode] = await Promise.all([proc.stdout.text(), proc.stderr.text(), proc.exited]);
+
+  expect(maxInFlight).toBe(limit);
+  expect(ctx.requested).toBe(limit + 1);
+  expect(stderr).toContain("failed to resolve");
+  expect(stdout).toContain("bun install v1.");
+  expect(exitCode).toBe(1);
+}
+
 const gitEnv = {
   ...bunEnv,
   GIT_AUTHOR_NAME: "bun-test",
@@ -121,6 +181,26 @@ function serveDirectory(root: string) {
 }
 
 describe.concurrent("bun-install", () => {
+  it("bun install --help states the --network-concurrency default that bun install actually uses", async () => {
+    await using help = spawn({
+      cmd: [bunExe(), "install", "--help"],
+      stdout: "pipe",
+      stderr: "pipe",
+      env,
+    });
+    const [helpStdout, helpStderr, helpExitCode] = await Promise.all([
+      help.stdout.text(),
+      help.stderr.text(),
+      help.exited,
+    ]);
+    const helpLine = (helpStdout + helpStderr).split(/\r?\n/).find(line => line.includes("--network-concurrency"));
+    const documentedDefault = /Maximum number of concurrent network requests \(default (\d+)\)$/.exec(helpLine ?? "");
+    expect(documentedDefault).not.toBeNull();
+    expect(helpExitCode).toBe(0);
+
+    await withContext(defaultOpts, ctx => expectInstallInFlightLimit(ctx, Number(documentedDefault![1])));
+  });
+
   for (let input of ["abcdef", "65537", "-1"]) {
     it(`bun install --network-concurrency=${input} fails`, async () => {
       await withContext(defaultOpts, async ctx => {