Workspace file utils throws: Cannot read property 'length' of undefined

Current Behavior

When running nx run mytarget:build --verbose it fails with

Cannot read property 'length' of undefined
TypeError: Cannot read property 'length' of undefined
    at Object.filesChanged (/.../node_modules/@nrwl/node/node_modules/@nrwl/workspace/src/core/file-utils.js:255:24)
    at Object.createProjectGraph (/.../node_modules/@nrwl/node/node_modules/@nrwl/workspace/src/core/project-graph/project-graph.js:21:32)
    at buildExecutor (/.../node_modules/@nrwl/node/src/executors/build/build.impl.js:28:39)
    at /.../node_modules/@nrwl/tao/src/commands/run.js:134:23
    at Generator.next (<anonymous>)
    at /.../node_modules/tslib/tslib.js:117:75
    at new Promise (<anonymous>)

Expected Behavior

It builds the target

Steps to Reproduce

Hard to tell issue is located inside

node_modules/@nrwl/node/node_modules/@nrwl/workspace/src/core/file-utils.js

function filesChanged(a, b) {
+  console.log(a,b)
+   if (a.length !== b?.length)
-   if (a.length !== b.length)
        return true;

The optional chaining on b does the trick and the console.log prints the following output:

[
  {
    file: 'package.json',
    hash: '1d085cde9f328c6fbe905dff7068ca8b70efdba0',
    ext: '.json'
  },
  {
    file: 'workspace.json',
    hash: '62266cc6a1d39f52da09833b25d8c6d545e46b19',
    ext: '.json'
  },
  {
    file: 'nx.json',
    hash: 'dcad049f2fa8f67840dc27514732a8992aae73aa',
    ext: '.json'
  },
  {
    file: 'tsconfig.base.json',
    hash: '11253ac5c2b7bc7ccc8003036c9379134582575c',
    ext: '.json'
  }
] undefined

Failure Logs

Cannot read property 'length' of undefined
TypeError: Cannot read property 'length' of undefined
    at Object.filesChanged (/.../node_modules/@nrwl/node/node_modules/@nrwl/workspace/src/core/file-utils.js:255:24)
    at Object.createProjectGraph (/.../node_modules/@nrwl/node/node_modules/@nrwl/workspace/src/core/project-graph/project-graph.js:21:32)
    at buildExecutor (/.../node_modules/@nrwl/node/src/executors/build/build.impl.js:28:39)
    at /.../node_modules/@nrwl/tao/src/commands/run.js:134:23
    at Generator.next (<anonymous>)
    at /.../node_modules/tslib/tslib.js:117:75
    at new Promise (<anonymous>)

Environment

 nx report

>  NX  Report complete - copy this into the issue template

  Node : 16.7.0
  OS   : darwin x64
  npm  : 7.20.3

  nx : 12.10.0
  @nrwl/angular : Not Found
  @nrwl/cli : 12.10.0
  @nrwl/cypress : 12.10.0
  @nrwl/devkit : 12.10.0
  @nrwl/eslint-plugin-nx : 12.10.0
  @nrwl/express : Not Found
  @nrwl/jest : 12.10.0
  @nrwl/linter : 12.10.0
  @nrwl/nest : 12.5.9
  @nrwl/next : Not Found
  @nrwl/node : 12.5.9
  @nrwl/nx-cloud : 12.3.13
  @nrwl/react : 12.10.0
  @nrwl/schematics : Not Found
  @nrwl/tao : 12.10.0
  @nrwl/web : 12.10.0
  @nrwl/workspace : 12.10.0
  @nrwl/storybook : 12.10.0
  @nrwl/gatsby : Not Found
  typescript : 4.4.4

[eromano]

rm -rf ./node_modules/.cache/nx

[edbzn]

Also ran into this issue, here is the report:

Node : 14.16.0
  OS   : linux x64
  yarn : 1.22.5
  
  nx : Not Found
  @nrwl/angular : 11.4.0
  @nrwl/cli : 11.4.0
  @nrwl/cypress : 11.4.0
  @nrwl/devkit : 11.4.0
  @nrwl/eslint-plugin-nx : 11.4.0
  @nrwl/express : Not Found
  @nrwl/jest : 11.4.0
  @nrwl/linter : 11.4.0
  @nrwl/nest : Not Found
  @nrwl/next : Not Found
  @nrwl/node : 11.4.0
  @nrwl/react : Not Found
  @nrwl/schematics : Not Found
  @nrwl/tao : 11.4.0
  @nrwl/web : Not Found
  @nrwl/workspace : 11.4.0
  typescript : 4.1.5

I had to kill the node_modules and re-install the dependencies to get rid of this.