Bun v0.5.1

Jarred Sumner · January 19, 2023

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Bun v0.5.1 adds support for aliasing package.json dependencies, a better error message when a workspace is not found, and a few important bug fixes. This release is a follow up to Bun v0.5.

# Install Bun
curl https://bun.sh/install | bash

# Upgrade to latest release of Bun
bun upgrade

Alias dependencies in package.json

bun install now supports aliasing dependencies via the npm: prefix (thanks to @alexlamsl)

This lets you install multiple versions of the same dependency and have it placed under a different folder in node_modules.


  "name": "all-the-lodashes",
  "dependencies": {
    "lodash": "^4.17.21",
    "lodash3": "npm:lodash@3"


const lodash3 = require("lodash3");
const lodash4 = require("lodash");



❯ bun index.ts


This feature is also supported by npm, yarn and others. Previously, when a package.json used this feature bun install showed an error message because it wasn't implemented yet.

Better error message when workspace is not found


bun install v0.5.0 (2db04ef9)

error: FileNotFound
bun could not find a file, and the code that produces this error is missing a better error.

----- bun meta -----
Bun v0.5.0 (2db04ef9) macOS Silicon 22.2.0
InstallCommand: bunfig
Elapsed: 4ms | User: 5ms | Sys: 9ms
RSS: 14.07MB | Peak: 14.07MB | Commit: 69.22MB | Faults: 12
----- bun meta -----


bun install v0.5.1 (f993975a)

error: Workspace not found "i-dont-exist" in "/private/tmp/bun-bad-workspace"

    "workspaces": ["i-dont-exist"]

For a package.json like this:

  "name": "my-workspace",
  "workspaces": ["i-dont-exist"]

Bug fixes

This release fixes a few important bugs

  • A regression introduced in v0.5.0 where reading the "encoding" string caused crashes
  • fetch was not wired up correctly to read the HTTPS_PROXY / HTTP_PROXY environment variables (fixed by @cirospaciari)
  • Assigning require to a variable caused undefined is not an object errors if used more than once #1831
  • A crash that sometimes occurred while processing long lists of workspace names
  • rmdir was missing from node:fs (fixed by @alexlamsl)
  • Error messages from BoringSSL were not being read correctly
  • Fixes a transpiler issue with TypeScript parameter fields in the constructor function. This regression was introduced when TypeScript decorators were implemented #1855 (fixed by @dylan-conway)


#1836Fix/simplify bun-types release by @colinhacks
#1838add fs.rmdir & friends by @alexlamsl
#1837support npm dependency aliasing by @alexlamsl
#1844fix(fetch:HTTP_PROXY) fix support for HTTP_PROXY/HTTPS_PROXY and NO_PROXY in fetch instances by @cirospaciari
#1827Create new example http-file-extended.ts by @gornostay25
#1848Bugfixes to install by @Jarred-Sumner
#1850use String.from() by @alexlamsl