Error [RollupError]: 'delete' cannot be called on an identifier in strict mode

[rmartins0]

Question

I'm trying to run pkgroll on a codebase but I'm getting stuck due to this error:

# yarn pkgroll
yarn run v1.22.22
$ /node_modules/.bin/pkgroll
Error [RollupError]: 'delete' cannot be called on an identifier in strict mode
    at getRollupError (file:///app/node_modules/rollup/dist/es/shared/parseAst.js:400:41)
    at convertProgram (file:///app/node_modules/rollup/dist/es/shared/parseAst.js:1088:26)
    at Object.parseAst [as parse] (file:///app/node_modules/rollup/dist/es/shared/parseAst.js:2073:87)
    at Object.transform (file:///app/node_modules/@rollup/plugin-dynamic-import-vars/dist/es/index.js:143:27)
    at file:///app/node_modules/rollup/dist/es/shared/node-entry.js:22249:40 {
  code: 'PLUGIN_ERROR',
  pos: 4602,
  pluginCode: 'PARSE_ERROR',
  plugin: 'commonjs--resolver',
  hook: 'resolveId',
  id: '/src/index.js',
  watchFiles: [

I'm not really sure which file is causing the problem since there are so many that use delete keyword. The log doesn't tell about a specific file.

For one thing, I want the build to work regardless of that. I was trying to pass an option to rollup to not be strict. https://rollupjs.org/configuration-options/#output-strict

But it doesn't seem there is a way to do that. Does anyone know?

[privatenumber]

Seems the error says your issue is in /src/index.js.

If you're writing in ESM, your code is inherently strict (you can't turn it off). The output-strict option is for non-ESM (e.g. CommonJS) source.

[rmartins0]

@privatenumber the code is in CommonJS and nowhere in index.js is delete used. It's used elsewhere in other files that are part of the bundle tree.

[privatenumber]

Is it being compiled to ESM?

Can you provide a minimal repro? Would be easier and faster to help you without this back and forth Q&A.