Here is how to reproduce the issue:

Failure:

1. Initialize empty project, create package json like this:

{
  "name": "ks-preconstruct",
  "version": "1.0.0",
  "main": "index.js",
  "license": "MIT",
  "private": true,
  "preconstruct": {
    "packages": [
      "keystone_core/packages/*",
      "keystone_core/design-system/packages/*",
      "keystone_core/prisma-utils"
    ]
  },
  "workspaces": {
    "packages": [
      "keystone_core/packages/*",
      "keystone_core/design-system/packages/*",
      "keystone_core/prisma-utils"
    ],
    "nohoist": [
      "**/cypress-multi-reporters"
    ]
  },
  "dependencies": {
    "@preconstruct/cli": "2.1.5"
  }
}

2. Download keystone to the subfolder keystone_core:

git clone https://github.com/keystonejs/keystone.git keystone_core

3. Run yarn install
4. Run the preconstruct validate process with grepping by next-config and see empty output:

$ npx preconstruct validate | grep next-config
<empty output>

Success:

1. Clone keystone project to empty directory:

git clone https://github.com/keystonejs/keystone.git && cd keystone

2. Run yarn install
3. Run the preconstruct validate process with grepping by next-config and see that those files are caught successfully:

$ npx preconstruct validate | grep next-config
🎁 info @keystone-6/core/___internal-do-not-use-will-break-in-patch/admin-ui/next-config a valid entry point exists.
🎁 info @keystone-6/core/___internal-do-not-use-will-break-in-patch/admin-ui/next-config main field is valid
🎁 info @keystone-6/core/___internal-do-not-use-will-break-in-patch/admin-ui/next-config module field is valid

So, where can be the source of that issue?

Seems this is an issue with fast-glob function, here is code to reproduce the problem:

const fg = require('fast-glob');

let entries;

entries = fg.sync([
  "keystone_core/packages/keystone/src/___internal-do-not-use-will-break-in-patch/admin-ui/{next-config.ts,id-field-view.tsx}",
  "keystone_core/packages/keystone/src/artifacts.ts"
], { dot: true });

console.log('expansions', entries);

entries = fg.sync([
  "keystone_core/packages/keystone/src/___internal-do-not-use-will-break-in-patch/admin-ui/id-field-view.tsx",
  "keystone_core/packages/keystone/src/___internal-do-not-use-will-break-in-patch/admin-ui/next-config.ts",
  "keystone_core/packages/keystone/src/artifacts.ts"
], { dot: true });

console.log('direct', entries);

and the output:

expansions [ 'keystone_core/packages/keystone/src/artifacts.ts' ]
direct [
  'keystone_core/packages/keystone/src/___internal-do-not-use-will-break-in-patch/admin-ui/id-field-view.tsx',
  'keystone_core/packages/keystone/src/___internal-do-not-use-will-break-in-patch/admin-ui/next-config.ts',
  'keystone_core/packages/keystone/src/artifacts.ts'
]

I've figured out the source of this problem, here is the issue: mrmlnc/fast-glob#351
Before it is solved, maybe good to lock it's version in preconstruct? Here is my PR with this #441

And here https://github.com/Murz-forks/preconstruct-cli-build is my compiled version of @preconstruct/cli with that fix, which can be installed quickly via:

  "dependencies": {
    "@preconstruct/cli": "Murz-forks/preconstruct-cli-build",
  }

This issue is fixed in fast-glob 3.2.11, so we should bump version.

I've found an easier way to force set deep dependency version - add to package.json this:

  "resolutions": {
    "@preconstruct/cli/fast-glob": "^3.2.11"
  }

Documentation is here https://classic.yarnpkg.com/en/docs/selective-version-resolutions/