No "exports" main defined on build or watch

Error on try build or watch.

mobile-web % yarn build
yarn build
yarn run v1.22.19
warning package.json: No license field
$ rollup -c

./src/viewer.js → ./dist/viewer.js...
[!] (plugin babel) Error: No "exports" main defined in /Users/aks/Downloads/amp-viewer-main/mobile-web/node_modules/@babel/helper-compilation-targets/package.json
src/viewer.js
Error [PLUGIN_ERROR]: No "exports" main defined in /Users/aks/Downloads/amp-viewer-main/mobile-web/node_modules/@babel/helper-compilation-targets/package.json
at new NodeError (node:internal/errors:388:5)
at throwExportsNotFound (node:internal/modules/esm/resolve:440:9)
at packageExportsResolve (node:internal/modules/esm/resolve:719:3)
at resolveExports (node:internal/modules/cjs/loader:488:36)
at Module._findPath (node:internal/modules/cjs/loader:528:31)
at Module._resolveFilename (node:internal/modules/cjs/loader:932:27)
at Module._load (node:internal/modules/cjs/loader:787:27)
at Module.require (node:internal/modules/cjs/loader:1012:19)
at require (node:internal/modules/cjs/helpers:102:18)
at Object. (/Users/aks/Downloads/amp-viewer-main/mobile-web/node_modules/@babel/preset-env/lib/debug.js:8:33)

error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

node: v18.4.0

Start in the mobile-web package, inspect package.json and the Rollup/Babel setup used by rollup -c, then reproduce the failure with Node v18.4.0 using yarn build and the watch command. Done means the build and watch workflows run without the reported @babel/helper-compilation-targets exports error.

Written by the indexing model from the issue text.