`overrides` with processor works unexpectedly

Tell us about your environment

• ESLint Version: 7.21.0
• Node Version: v14.16.0
• npm Version: 7.5.6
• Operating System: GNU/Linux 5.4.0-1024-gcp

What parser (default, @babel/eslint-parser, @typescript-eslint/parser, etc.) are you using?

Default

Please show your full configuration:

https://github.com/JounQin/test/blob/eslint/.eslintrc.js

What did you do? Please include the actual source code causing the issue, as well as the command that you used to run ESLint.

https://github.com/JounQin/test/blob/eslint/test.cjs

yarn eslint test.cjs

What did you expect to happen?

No error because prettier is intended to be disabled

What actually happened? Please copy-paste the actual, raw output from ESLint.

Oops! Something went wrong! :(

ESLint: 7.21.0

Error: ENOTDIR: not a directory, stat '/workspace/test/test.cjs/0_.cjs'
Occurred while linting /workspace/test/test.cjs/0_.cjs:1
    at Object.statSync (fs.js:1086:3)
    at isTypeSync (/workspace/test/node_modules/prettier/third-party.js:9748:46)
    at getDirectorySync (/workspace/test/node_modules/prettier/third-party.js:9802:62)
    at ExplorerSync.searchSync (/workspace/test/node_modules/prettier/third-party.js:9950:66)
    at _resolveConfig (/workspace/test/node_modules/prettier/index.js:25592:50)
    at Function.resolveConfig.sync (/workspace/test/node_modules/prettier/index.js:25621:42)
    at Program (/workspace/test/node_modules/eslint-plugin-prettier/eslint-plugin-prettier.js:167:40)
    at /workspace/test/node_modules/eslint/lib/linter/safe-emitter.js:45:58
    at Array.forEach (<anonymous>)
    at Object.emit (/workspace/test/node_modules/eslint/lib/linter/safe-emitter.js:45:38)

Steps to reproduce this issue:

1. clone https://github.com/JounQin/test/tree/eslint or open https://turquoise-limpet-v0as7arg.ws-us03.gitpod.io/
2. run yarn eslint test.cjs, there will be an error
3. toggle the comment in .eslintrc.js and run yarn eslint test.cjs again, there will be no error, but it is not expected, I want to check test.cjs with prettier but disable it on code block

Are you willing to submit a pull request to fix this bug?

I don’t know how to fix it easily.

[nzakas]

I think this is a bug. We probably did this for performance reasons, since calculating configs is expensive.

I’m also guessing this use case is fairly uncommon so fixing this bug doesn’t seem like a breaking change to me.

[btmills]

I agree this is a bug that we can fix in a semver-minor change.