SyntaxError when running build script

[natebuckareff]

Running the following on a fresh clone:

pnpm install
pnpm build 18.0.0

Gives the error:

> readable-stream@4.5.2 build /tmp/readable-stream
> node build/build.mjs "18.0.0"

[INFO] Downloading https://nodejs.org/dist/v18.0.0/node-v18.0.0.tar.gz ...
[INFO] Extracting Node.js 18.0.0 tar file ...
[INFO] extraction done
[INFO] Creating directory lib ...
[INFO] Creating directory lib/stream ...
[INFO] Creating directory lib/internal ...
[INFO] Creating directory lib/internal/streams ...
[INFO] Creating directory test/common ...
[INFO] Creating directory test/parallel ...
[INFO] Creating directory test/fixtures ...
[INFO] Creating directory lib/ours ...
[INFO] Creating directory test/ours ...
[INFO] Creating directory test/browser ...
[INFO] Creating directory test/browser/fixtures ...
[INFO] Creating file lib/_stream_transform.js (replacements, babel, prettier) ...
[INFO] Creating file lib/_stream_duplex.js (replacements, babel, prettier) ...
[INFO] Creating file lib/stream/promises.js (replacements, babel, prettier) ...
[INFO] Creating file lib/internal/validators.js (replacements, babel, prettier) ...
[INFO] Creating file lib/internal/streams/add-abort-signal.js (replacements, babel, prettier) ...
/tmp/readable-stream/node_modules/.pnpm/@babel+parser@7.26.2/node_modules/@babel/parser/lib/index.js:359
    const error = new SyntaxError();
                  ^

SyntaxError: unknown: Expecting Unicode escape sequence \uXXXX. (21:8)

  19 |   validateObject,
  20 | } = require('../validators');
> 21 | require\('../event_target'\);const kWeakHandler = require('../../ours/primordials').Symbol('kWeak');
     |         ^
  22 | const { finished } = require('./end-of-stream');
  23 |
  24 | const {
    at constructor (/tmp/readable-stream/node_modules/.pnpm/@babel+parser@7.26.2/node_modules/@babel/parser/lib/index.js:359:19)
    at Parser.raise (/tmp/readable-stream/node_modules/.pnpm/@babel+parser@7.26.2/node_modules/@babel/parser/lib/index.js:3266:19)
    at Parser.readWord1 (/tmp/readable-stream/node_modules/.pnpm/@babel+parser@7.26.2/node_modules/@babel/parser/lib/index.js:3226:16)
    at Parser.readWord (/tmp/readable-stream/node_modules/.pnpm/@babel+parser@7.26.2/node_modules/@babel/parser/lib/index.js:3246:23)
    at Parser.getTokenFromCode (/tmp/readable-stream/node_modules/.pnpm/@babel+parser@7.26.2/node_modules/@babel/parser/lib/index.js:2969:16)
    at Parser.nextToken (/tmp/readable-stream/node_modules/.pnpm/@babel+parser@7.26.2/node_modules/@babel/parser/lib/index.js:2449:10)
    at Parser.next (/tmp/readable-stream/node_modules/.pnpm/@babel+parser@7.26.2/node_modules/@babel/parser/lib/index.js:2362:10)
    at Parser.eat (/tmp/readable-stream/node_modules/.pnpm/@babel+parser@7.26.2/node_modules/@babel/parser/lib/index.js:2366:12)
    at Parser.isLineTerminator (/tmp/readable-stream/node_modules/.pnpm/@babel+parser@7.26.2/node_modules/@babel/parser/lib/index.js:3588:17)
    at Parser.semicolon (/tmp/readable-stream/node_modules/.pnpm/@babel+parser@7.26.2/node_modules/@babel/parser/lib/index.js:3591:25)
    at Parser.parseVarStatement (/tmp/readable-stream/node_modules/.pnpm/@babel+parser@7.26.2/node_modules/@babel/parser/lib/index.js:12725:10)
    at Parser.parseStatementContent (/tmp/readable-stream/node_modules/.pnpm/@babel+parser@7.26.2/node_modules/@babel/parser/lib/index.js:12340:23)
    at Parser.parseStatementLike (/tmp/readable-stream/node_modules/.pnpm/@babel+parser@7.26.2/node_modules/@babel/parser/lib/index.js:12257:17)
    at Parser.parseModuleItem (/tmp/readable-stream/node_modules/.pnpm/@babel+parser@7.26.2/node_modules/@babel/parser/lib/index.js:12234:17)
    at Parser.parseBlockOrModuleBlockBody (/tmp/readable-stream/node_modules/.pnpm/@babel+parser@7.26.2/node_modules/@babel/parser/lib/index.js:12810:36)
    at Parser.parseBlockBody (/tmp/readable-stream/node_modules/.pnpm/@babel+parser@7.26.2/node_modules/@babel/parser/lib/index.js:12803:10)
    at Parser.parseProgram (/tmp/readable-stream/node_modules/.pnpm/@babel+parser@7.26.2/node_modules/@babel/parser/lib/index.js:12131:10)
    at Parser.parseTopLevel (/tmp/readable-stream/node_modules/.pnpm/@babel+parser@7.26.2/node_modules/@babel/parser/lib/index.js:12121:25)
    at Parser.parse (/tmp/readable-stream/node_modules/.pnpm/@babel+parser@7.26.2/node_modules/@babel/parser/lib/index.js:13929:10)
    at parse (/tmp/readable-stream/node_modules/.pnpm/@babel+parser@7.26.2/node_modules/@babel/parser/lib/index.js:13963:38)
    at parser (/tmp/readable-stream/node_modules/.pnpm/@babel+core@7.26.0/node_modules/@babel/core/lib/parser/index.js:41:34)
    at parser.next (<anonymous>)
    at normalizeFile (/tmp/readable-stream/node_modules/.pnpm/@babel+core@7.26.0/node_modules/@babel/core/lib/transformation/normalize-file.js:64:37)
    at normalizeFile.next (<anonymous>)
    at run (/tmp/readable-stream/node_modules/.pnpm/@babel+core@7.26.0/node_modules/@babel/core/lib/transformation/index.js:22:50)
    at run.next (<anonymous>)
    at transform (/tmp/readable-stream/node_modules/.pnpm/@babel+core@7.26.0/node_modules/@babel/core/lib/transform.js:22:33)
    at transform.next (<anonymous>)
    at evaluateSync (/tmp/readable-stream/node_modules/.pnpm/gensync@1.0.0-beta.2/node_modules/gensync/index.js:251:28)
    at sync (/tmp/readable-stream/node_modules/.pnpm/gensync@1.0.0-beta.2/node_modules/gensync/index.js:89:14)
    at stopHiding - secret - don't use this - v1 (/tmp/readable-stream/node_modules/.pnpm/@babel+core@7.26.0/node_modules/@babel/core/lib/errors/rewrite-stack-trace.js:47:12)
    at transform (/tmp/readable-stream/node_modules/.pnpm/@babel+core@7.26.0/node_modules/@babel/core/lib/transform.js:36:80)
    at processFiles (file:///tmp/readable-stream/build/build.mjs:129:39)
    at async main (file:///tmp/readable-stream/build/build.mjs:227:3)
    at async file:///tmp/readable-stream/build/build.mjs:230:1 {
  code: 'BABEL_PARSE_ERROR',
  reasonCode: 'MissingUnicodeEscape',
  loc: Position { line: 21, column: 8, index: 370 },
  pos: 370,
  syntaxPlugin: undefined
}

Node.js v20.13.1
 ELIFECYCLE  Command failed with exit code 1.

Looks like the problem is a typoed \\ in build/replacements.mjs:internalStreamsWeakHandler. PR with fix here: #544

[MattiasBuelens]

Fixed in #544.