Detect Chrome phased rollouts

Question

How can phased rollouts be debugged in Chrome? Is there a screen which shows "you are in rollout group A" or B ?

Same #Chrome Version 70.0.3538.102 (Official Build) (64-Bit) version, for me the cert does not work (first screenshot), for my colleague it still does (second screenshot).

The About Screen shows the same version.

Answer 1

Unfortunately, this is (intentionally) difficult.

Since you know exactly what feature is causing trouble, you can force it with either --enable-features=LegacySymantecPKI or --disable-features=LegacySymantecPKI.

If you want to roll the dice, that's --reset-variation-state, and you can view the current variations at chrome://version. Since the variation state only has 13 bits of entropy¹, there will be a large overlap in which variations are toggled together, so you'll have a hard time determining which hashed feature in this list corresponds to LegacySymantecPKI, Disabled, and Enabled.

There's a feature request to show the unhashed field trial names: https://crbug.com/653634.

There's a design doc for the hashing here: https://cs.chromium.org/chromium/src/components/variations/variations_murmur_hash.h