Getting `EISDIR: illegal operation on a directory` when migrating from 8.x to 9.0

Reproduction

Steps to reproduce:

1. ng update @angular/cdk

Because there is not enough information provided by the migration, I am unable to provide a reproduction stackblitz.

Expected Behavior

Successful migration to v9, or at least a meaningful error message that tells me where something might be wrong.

Actual Behavior

What behavior did you actually see?

EISDIR: illegal operation on a directory, read
✖ Migration failed. See above for further details.

Any help is much appreciated🙏

Environment

• Angular: 9
• CDK/Material: 8.2.1 -> 9.0.0
• Browser(s): N/A
• Operating System (e.g. Windows, macOS, Ubuntu): OSX

The error seemed similar to this issue https://github.com/angular/angular/issues/31056, but all the examples in that repo shows that additional error information

$ ng update @angular/cdk --verbose
Locating potential npmrc files:
Trying '/usr/local/etc/npmrc'...not found.
Trying '/Users/foo/.npmrc'...found.
Trying '/Users/.npmrc'...not found.
Trying '/Users/foo/.npmrc'...found.
Trying '/Users/foo/dev/.npmrc'...not found.
Trying '/Users/foo/dev/node/.npmrc'...not found.
Trying '/Users/foo/dev/node/fusekit/.npmrc'...found.
Using package manager: 'npm'
Collecting installed dependencies...
Found 186 dependencies.
Fetching dependency metadata from registry...
    Locating potential npmrc files:
    Trying '/usr/local/etc/npmrc'...not found.
    Trying '/Users/foo/.npmrc'...found.
    Trying '/Users/.npmrc'...not found.
    Trying '/Users/foo/.npmrc'...found.
    Trying '/Users/foo/dev/.npmrc'...not found.
    Trying '/Users/foo/dev/node/.npmrc'...not found.
    Trying '/Users/foo/dev/node/fusekit/.npmrc'...found.
    Updating package.json with dependency @angular/cdk @ "9.0.0" (was "8.2.1")...
UPDATE package.json (9582 bytes)
✔ Packages installed successfully.
** Executing migrations of package '@angular/cdk' **

❯ Updates the Angular CDK to v9
EISDIR: illegal operation on a directory, read
✖ Migration failed. See above for further details.

$ 

[devversion]

Thanks @paustint for all the information. This helps a lot. I think there are a few things we could do:

1. Make sure that we don’t glob for directories matching the style extension.
2. Do not depend on globs for finding global project stylesheets which are not part of a component.
   • We can do this by consulting the angular.json file and styles configuration.

Long-term we should explore (2) as using a glob is obviously not ideal.

[paustint]

OK - I found out some possible useful information.

1. When I ran the migration from the node_modules/@angular directory, the migration was successful and 0 files aside from package.json and package-lock.json were updated (which means I likely do not have anything to migrate)
2. When I ran the migration from the project root, after making the cli change, I get the following error message:

An unhandled exception occurred: EISDIR: illegal operation on a directory, read
See "/private/var/folders/l0/wtqgh8410tj2s_vz_n6h18y00000gp/T/ng-ZKRRHi/angular-errors.log" for further details

And that log shows this:

[error] Error: EISDIR: illegal operation on a directory, read
    at Object.readSync (fs.js:513:3)
    at tryReadSync (fs.js:338:20)
    at Object.readFileSync (fs.js:375:19)
    at ComponentResourceCollector.resolveExternalStylesheet (/Users/foo/dev/node/foo/node_modules/@angular/cdk/schematics/update-tool/component-resource-collector.js:137:38)
    at /Users/foo/dev/node/foo/node_modules/@angular/cdk/schematics/update-tool/index.js:87:50
    at Array.forEach (<anonymous>)
    at Object.runMigrationRules (/Users/foo/dev/node/foo/node_modules/@angular/cdk/schematics/update-tool/index.js:86:14)
    at runMigration (/Users/foo/dev/node/foo/node_modules/@angular/cdk/schematics/ng-update/upgrade-rules/index.js:77:46)
    at /Users/foo/dev/node/foo/node_modules/@angular/cdk/schematics/ng-update/upgrade-rules/index.js:80:37
    at Array.forEach (<anonymous>)
    at Object.<anonymous> (/Users/foo/dev/node/foo/node_modules/@angular/cdk/schematics/ng-update/upgrade-rules/index.js:80:24)
    at Generator.next (<anonymous>)
    at /Users/foo/dev/node/foo/node_modules/@angular/cdk/schematics/ng-update/upgrade-rules/index.js:14:71
    at new Promise (<anonymous>)
    at __awaiter (/Users/foo/dev/node/foo/node_modules/@angular/cdk/schematics/ng-update/upgrade-rules/index.js:10:12)
    at /Users/foo/dev/node/foo/node_modules/@angular/cdk/schematics/ng-update/upgrade-rules/index.js:61:35