What steps will reproduce the problem?
(1) Go to https://chrome-infra-packages.appspot.com/#/?path=infra/tools/mac_toolchain

What is the expected result?
The infra/tools/mac_toolchain package prefix page loads

What happens instead?
Just a blank white rectangle loads

Console log:
Uncaught TypeError: Cannot read property 'repo' of undefined
    at HTMLElement.populatePage ((index):12592)
    at HTMLElement._observerEffect ((index):3311)
    at HTMLElement.<anonymous> ((index):3170)
    at Array.forEach (<anonymous>)
    at HTMLElement._effectEffects ((index):3167)
    at HTMLElement._propertySet ((index):3161)
    at HTMLElement.setter ((index):3228)
    at c ((index):5938)
    at u ((index):5938)
    at r ((index):5938)
(index):12685 API loaded.
(index):12686 Uncaught TypeError: Cannot read property 'firstChild' of undefined
    at HTMLElement._apiLoaded ((index):12686)
    at HTMLElement.handler ((index):2418)
    at HTMLElement.fire ((index):3075)
    at HTMLElement._fireSuccess ((index):12105)
    at HTMLElement._handleLoadResponse ((index):12100)
    at cb=gapi.loaded_1:504
    at f (cb=gapi.loaded_1:501)
    at h.r2 (cb=gapi.loaded_0:115)
    at xs (cb=gapi.loaded_0:118)
    at Wq (cb=gapi.loaded_0:118)