cypress: doc.createTreeWalker is not a function

Current behavior

When running a Cypress test via the Test Runner:

node ./cypress/cypress.js -- open

I’m seeing this error thrown from cypress:

cypress_runner.js:175886 TypeError: doc.createTreeWalker is not a function
    at findShadowRoots (https://localhost:8080/__cypress/runner/cypress_runner.js:166508:22)
    at collectRoots (https://localhost:8080/__cypress/runner/cypress_runner.js:166488:24)
    at Object.findAllShadowRoots (https://localhost:8080/__cypress/runner/cypress_runner.js:166498:10)
    at getElements (https://localhost:8080/__cypress/runner/cypress_runner.js:143851:45)
From previous event:
    at resolveElements (https://localhost:8080/__cypress/runner/cypress_runner.js:143905:27)
    at $Cy.get (https://localhost:8080/__cypress/runner/cypress_runner.js:143916:14)
    at $Cy.now (https://localhost:8080/__cypress/runner/cypress_runner.js:156327:47)
    at resolveElements (https://localhost:8080/__cypress/runner/cypress_runner.js:144084:19)
From previous event:
    at tryFn (https://localhost:8080/__cypress/runner/cypress_runner.js:151739:21)
    at whenStable (https://localhost:8080/__cypress/runner/cypress_runner.js:151777:12)
    at https://localhost:8080/__cypress/runner/cypress_runner.js:151269:16
From previous event:
    at $Cy.retry (https://localhost:8080/__cypress/runner/cypress_runner.js:151249:38)
    at onFailFn (https://localhost:8080/__cypress/runner/cypress_runner.js:135999:19)
From previous event:
    at $Cy.verifyUpcomingAssertions (https://localhost:8080/__cypress/runner/cypress_runner.js:136006:63)
    at https://localhost:8080/__cypress/runner/cypress_runner.js:144090:21
From previous event:
    at resolveElements (https://localhost:8080/__cypress/runner/cypress_runner.js:144084:52)
    at tryFn (https://localhost:8080/__cypress/runner/cypress_runner.js:151739:21)
    at whenStable (https://localhost:8080/__cypress/runner/cypress_runner.js:151777:12)
    at https://localhost:8080/__cypress/runner/cypress_runner.js:151269:16

Desired behavior

No error is thrown

Test code to reproduce

I can’t share the full source code due to my company’s policies. Maybe a simpler repro could be made once I have some idea of where this issue is coming from.

The line of code where this is failing is cy.findByRole('tabpanel', { hidden: false }).findByTestId('RichCommandFooter').contains('runtime');

Cypress Version

8.1.0

Other

Happy to provide more details. Our cypress.js file has a good amount going on it, but I’m not sure what would be most relevant to help debug.

@testing-library/cypress is on version 8.0.1