Bun v1.0.17

Jarred Sumner · December 12, 2023

Bun v1.0.17 fixes 15 bugs (addressing 152 👍 reactions). bun install postinstall scripts run for top 500 packages, bunx supabase starts 30x faster than npx supabase, bunx esbuild starts 50x faster than npx esbuild and bugfixes to bun install

Bun is an incredibly fast JavaScript runtime, bundler, transpiler, and package manager — all in one. In case you missed it, here are some of the recent changes to Bun:

  • v1.0.13 - Fixes 6 bugs (addressing 317 👍 reactions). 'http2' module & gRPC.js work now. Vite 5 & Rollup 4 work. Implements process.report.getReport(), improves support for ES5 'with' statements, fixes a regression in bun install, fixes a crash when printing exceptions, fixes a Bun.spawn bug, and fixes a peer dependencies bug
  • v1.0.14 - Bun.Glob, a fast API for matching files and strings using glob patterns. It also fixes a race condition when extracting dependencies during bun install, improves TypeScript module resolution in node_modules, and makes error messages easier to read.
  • v1.0.15 - Fixes 23 bugs (addressing 117 👍 reactions), tsc starts 2x faster. Stable WebSocket client, syntax-highlighted errors, cleaner stack traces, add custom test matchers with expect.extend() + additional expect matchers.
  • v1.0.16 - Fixes 49 bugs (addressing 38 👍 reactions). Concurrent IO for Bun.file & Bun.write gets 3x faster and now supports Google Cloud Run & Vercel, Bun.write auto-creates the parent directory if it doesn't exist, expect.extend inside of preload works, napi_create_object gets 2.5x faster, bugfix for module resolution impacting Astro v4 and p-limit, console.log bugfixes

To install Bun:

curl -fsSL https://bun.sh/install | bash
npm install -g bun
brew tap oven-sh/bun
brew install bun
docker pull oven/bun
docker run --rm --init --ulimit memlock=-1:-1 oven/bun

To upgrade Bun:

bun upgrade

bun install now runs lifecycle scripts for the top 500 npm packages

In this release, we've added the top 500 most-downloaded npm packages in a default allowlist to run lifecycle scripts during bun install. This means that bun install will now run preinstall, install, and postinstall scripts for the top 500 npm packages which have them defined.

This addresses many issues with bun install:

Thanks to @dylan-conway and @paperdave for implementing this.

Lifecycle scripts now run in parallel

As part of the above work, we also made lifecycle scripts run in parallel, which reduces the impact of lifecycle scripts on installation time.

⚙️ emoji appears when the lifecycle script is running

Configuring concurency

You can configure the maximum number of concurrent lifecycle scripts that run at once either by


# Only run 5 in parallel at max
install.concurrentScripts = 5

CLI argument:

bun install --concurrent-scripts=5

Environment variable:

GOMAXPROCS=2 bun install

Note: it is $GOMAXPROCS because we use that elsewhere and it's one less environment variable for us to make up a name for (it's what Go uses, but Bun doesn't use Go).

Error message improvement in bun install

When a permissions error occurs, bun install now shows a more helpful error message. Instead of just "Unexpected", it now provides more information when it can.

Left: before, Right: after

Thanks to @paperdave for implementing this.

Fixed: Semver pre-release sorting bug

A crash that could occur when sorting many pre-release versions of specific input simultaneously has been fixed. This bug was fixed by @dylan-conway. This bug could be reproduced when installing 4 year old versions of Gatsby.

Fixed: lifecycle script dependency install order

A bug where bun install would install lifecycle scripts without first ensuring all dependent lifecycle scripts were installed has been fixed. This bug was fixed by @dylan-conway.

bunx supabase starts 30x faster than npx supabase

Since bun install now enables lifecycle scripts for popular packages by default, bunx supabase now works.

On Linux x64, bun x supabase starts 30x faster than npx supabase:

Benchmark 1: bun x supabase
  Time (mean ± σ):      10.5 ms ±   1.0 ms    [User: 8.0 ms, System: 5.5 ms]
  Range (min … max):     8.5 ms …  13.1 ms    248 runs

Benchmark 2: npx supabase
  Time (mean ± σ):     325.2 ms ±  30.6 ms    [User: 272.6 ms, System: 117.9 ms]
  Range (min … max):   291.0 ms … 389.9 ms    10 runs

  bun x supabase ran
   30.90 ± 4.17 times faster than npx supabase

bunx esbuild starts 50x faster than npx esbuild

Now that bun install enables lifecycle scripts for popular packages by default, bunx esbuild now starts roughly 50x faster than npx esbuild:

Benchmark 1: bun x esbuild --help
  Time (mean ± σ):       3.5 ms ±   0.3 ms    [User: 1.8 ms, System: 1.6 ms]
  Range (min … max):     2.8 ms …   4.3 ms    827 runs

Benchmark 2: npx esbuild --help
  Time (mean ± σ):     295.7 ms ±  23.8 ms    [User: 270.0 ms, System: 100.6 ms]
  Range (min … max):   259.6 ms … 339.6 ms    10 runs

  bun x esbuild --help ran
   83.84 ± 9.31 times faster than npx esbuild --help

-h is now an alias of --help

-h is now an alias of --help for all commands. Thanks to @hustLer2k for implementing this.

$ bun -h

Bun is a fast JavaScript runtime, package manager, bundler, and test runner. (1.0.16 (a2f595d3))

Usage: bun <command> [...flags] [...args]

  run       ./my-script.ts       Execute a file with Bun
            lint                 Run a package.json script
  test                           Run unit tests with Bun
  x         vite                 Execute a package binary (CLI), installing if needed (bunx)
  repl                           Start a REPL session with Bun

  install                        Install dependencies for a package.json (bun i)
  add       svelte               Add a dependency to package.json (bun a)
  remove    babel-core           Remove a dependency from package.json (bun rm)
  update    lodash               Update outdated dependencies
  link      [<package>]          Register or link a local npm package
  unlink                         Unregister a local npm package
  pm <subcommand>                Additional package management utilities

  build     ./a.ts ./b.jsx       Bundle TypeScript & JavaScript into a single file

  init                           Start an empty Bun project from a blank template
  create                         Create a new project from a template (bun c)
  upgrade                        Upgrade to latest version of Bun.
  <command> --help               Print help text for command.

      --watch                    Automatically restart the process on file change
      --hot                      Enable auto reload in the Bun runtime, test runner, or bundler
      --smol                     Use less memory, but run garbage collection more often
  -r, --preload                  Import a module before other modules are loaded
      --inspect                  Activate Bun's debugger
      --inspect-wait             Activate Bun's debugger, wait for a connection before executing
      --inspect-brk              Activate Bun's debugger, set breakpoint on first line of code and wait
      --if-present               Exit without an error if the entrypoint does not exist
      --no-install               Disable auto install in the Bun runtime
      --install                  Configure auto-install behavior. One of "auto" (default, auto-installs when no node_modules), "fallback" (missing packages only), "force" (always).
  -i                             Auto-install dependencies during execution. Equivalent to --install=fallback.
  -e, --eval                     Evaluate argument as a script
      --prefer-offline           Skip staleness checks for packages in the Bun runtime and resolve from disk
      --prefer-latest            Use the latest matching versions of packages in the Bun runtime, always checking npm
  -p, --port                     Set the default port for Bun.serve
  -b, --bun                      Force a script or package to use Bun's runtime instead of Node.js (via symlinking node)
      --silent                   Don't print the script command
  -v, --version                  Print version and exit
      --revision                 Print version with revision and exit
      --env-file                 Load environment variables from the specified file(s)
      --cwd                      Absolute path to resolve files & entry points from. This just changes the process' cwd.
  -c, --config                   Specify path to Bun config file. Default $cwd/bunfig.toml
  -h, --help                     Display this menu and exit

(more flags in bun install --help, bun test --help, and bun build --help)

Learn more about Bun:            https://bun.sh/docs
Join our Discord community:      https://bun.sh/discord

Fixed: encoding argument in fs.createReadStream

A bug where the encoding argument in fs.createReadStream was not handled correctly has been fixed. This bug was fixed by @hustLer2k.

Thanks to 6 contributors!