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Starred by 13 users

Issue metadata

Status: WontFix
Owner: ----
Closed: Apr 2016
EstimatedDays: ----
NextAction: ----
OS: Windows
Pri: 2
Type: Bug

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Issue 602023: Canary 64-bit incorrectly updates to 32-bit

Reported by, Apr 9 2016

Issue description

UserAgent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:48.0) Gecko/20100101 Firefox/48.0

Steps to reproduce the problem:
1. Install Canary 64-bit
2. Successfully install a couple nightly updates (over a few days) 
3. On about the 3rd or 4th nightly update, the relaunch will take forever and then the Canary will finally show up, but as "Not Responding"
4. Task Manage will show Canary as a 32-bit process 

What is the expected behavior?
64-bit Canary should successfully update to 64-bit Canary

What went wrong?
64-bit Canary updated to 32-bit Canary. Screenshot of Task Manager is attached.

Did this work before? Yes Last week

Chrome version: 51.0.2703.1  Channel: canary
OS Version: 10.0
Flash Version: Shockwave Flash 21.0 r0
48.1 KB View Download

Comment 1 by, Apr 9 2016

I should add that the only resolution I've been able to find is to reinstall Canary 64-bit from

Comment 2 by, Apr 10 2016

Status: WontFix (was: Unconfirmed)
On occasion, we send a 32-bit build to 64-bit installs. The most frequent case is an ASAN build to help us find memory-related bugs in Chrome. It's most likely that you received one of these build (chrome://version will tell you), and that you'd be back to 64-bit canary the next day.

Comment 3 by, Apr 10 2016

1. "Occasionally?" I've had this happen on multiple machines in one week.
2. I'm all for testing, but is it supposed to KO the user's Chrome installation in the manner it currently does? As shown in the screenshot Chrome's CPU usage soars (while still not showing up as a window), and then the window is "Not Responding" when it does show up.

Is there a better way of doing this that doesn't make the browser totally inoperable?

Comment 4 by, Apr 12 2016

Some background: We've recently started shipping ASAN instrumented builds of Chrome to canary users. These builds contain instrumentation that track down heap memory errors, and provide extremely useful bug reports to Chrome developers. As grt@ mentions, if you're on one of these builds you'll see a 'SyzyASan' label if you navigate to chrome://version.

- To limit user pain we filter for machines with sufficient memory, as there is a significant memory overhead to the instrumentation.

- To further limit user pain we randomly select 1 in every 20 users every day. That is, for any day's update you have a 1 in 20 chance of receiving an ASAN instrumented build. The next days update still has the same 1 in 20 chance, so most often you should end up back on a non-instrumented build.

- Unfortunately, the technology is 32-bit only right now. In order to increase the audience of potential users we also ship to 64-bit users, intentionally downgrading them to 32-bit builds for a day.

We are working on making the instrumentation work natively in 64-bit mode, but that is at least 6 months away.

Finally, if the instrumentation is rendering your browser completely unusable we do have an opt-out mechanism in place.

Comment 5 by, Apr 12 2016


Comment 6 by, Apr 12 2016

Thanks for the background and information! Makes better sense now. At least the crash can be fixed by doing an in-place reinstallation.

Comment 7 by, Apr 20 2016

BTW, what's the opt-out mechanism?

Comment 8 by, Apr 20 2016

Open the following folder in regedit: HKCU\Software\Google\Update\ClientState\{4EA16AC7-FD5A-47C3-875B-DBF4A2008C20}\cohort

Then look for or create a string key named hint, and set the value to asan-optout

You can also just open a command prompt and run:

reg add HKCU\Software\Google\Update\ClientState\{4EA16AC7-FD5A-47C3-875B-DBF4A2008C20}\cohort /v hint /d asan-optout /f

Comment 9 by, Oct 12 2016

Can you guys put an end to this insane, unreasonable, and discriminatory (against Windows users) practice? It absolutely ruins UX. Just now my Chrome instance froze up and my CPU usage hit 99%. Checking Task Manager revealed Chrome 32-bit was responsible. There's no way anyone could consider this sensible behavior by any application, even one in alpha mode. C'mon guys, cut it out already.

Comment 10 by, Oct 12 2016

BTW, running the Chrome 64-bit installer no longer fixes the problem, so now users are left with a completely unusable Chrome installation. ***How is this a good idea on any level???*** It's the equivalent of knowingly pushing malware to users' PCs. And don't tell me it's OK because it's Canary. The point of Canary is to test unstable new features, not *deliberately* bork end user functionality.

Comment 11 by, Oct 12 2016

It gets worse: trying to uninstall Chrome fires up the 32-bit (are you kidding me?) uninstaller, which of course promptly crashes and makes uninstallation take forever. Please, please, please stop this madness.

Comment 12 by, Oct 14 2016

The opt-out mechanism listed in comment #8 should prevent this from occurring to you in the future. If you are still suffering from this problem, there is likely something else at fault.

Can you confirm the full version string reported at the top of the page when you visit chrome://version ?

Comment 13 by, Oct 25 2016

I did the opt-out command and I'm still receiving broken 32-bit builds. I can't tell you anything about version string because Chrome crashes/freezes up/takes 99% of CPU when I launch it.

Please stop this practice overall. I'm sure there are plenty of VMs in the cloud you can test on.

Comment 14 by, Oct 25 2016

WTF: I downloaded the Chrome 64-bit installer and got a 32-bit build! Oh COME ON. Is this for real? How does this help the end user or testing in any way?

Comment 15 by, Oct 25 2016

@chrisha: My point is this shouldn't be happening in the 1st place. It's totally unreasonable to push broken builds to users like that. It's also deceptive to install a 32-bit build on a 64-bit user's machine. Deploy those builds to VMs if you want to test.

Comment 16 by, Dec 18 2016

It happened again. What are you guys doing, seriously? Is anyone trying to fix this problem?

Comment 17 by, Dec 20 2016

Could you confirm that the "hint" value in this registry key is set to "asan-optout"?

reg query HKCU\Software\Google\Update\ClientState\{4EA16AC7-FD5A-47C3-875B-DBF4A2008C20}\cohort

Comment 18 by, Dec 20 2016

I ran that command and got the attached result, which I don't really know the meaning of. 

Again, my request is that this practice be stopped. There's no logical reason why a user who deliberately selected a 64-bit build should be pushed a broken 32-bit one.
9.9 KB View Download

Comment 19 by, Dec 20 2016

We totally understand that you find the ASAN builds frustrating. As Chris pointed out in comment 4, the ASAN builds on the canary channel help us find stability and security bugs in Chrome before they reach the stable channel.

Run the command Seb provided in comment #8:

reg add HKCU\Software\Google\Update\ClientState\{4EA16AC7-FD5A-47C3-875B-DBF4A2008C20}\cohort /v hint /d asan-optout /f

and a day or so later your machine will be back to the 64-bit builds and will no longer receive the 32-bit ASAN builds. Note that if you uninstall canary and re-install it, you will need to run this command again.

We would love for you to continue to use canary Chrome and file useful feedback so we can make the browser as awesome as possible.


Comment 20 by, Jan 3 2017

That command doesn't work. I ran *again* after my previous post and once again today I got a busted 32-bit build pushed to me. 

Again, why do you need to do this to users? Why not use VMs?

Comment 21 by, Jan 3 2017

*Ran it again

Comment 22 by, Jan 3 2017

Very odd. What do you see for the "hint" value when you run the following from a CMD prompt:

reg query HKCU\Software\Google\Update\ClientState\{4EA16AC7-FD5A-47C3-875B-DBF4A2008C20}\cohort

Comment 23 by, Jan 4 2017

I get "REG_SZ," but this is after I reapplied 
reg add HKCU\Software\Google\Update\ClientState\{4EA16AC7-FD5A-47C3-875B-DBF4A2008C20}\cohort /v hint /d asan-optout /f so I'm not sure if it's useful.

Comment 24 by, Jan 4 2017

If you see
    hint    REG_SZ    asan-optout
then you're golden. This is what you should expect if you run the "query" command immediately following the "add" command.

If, on the other hand, you see:
    hint    REG_SZ
then you have a random chance of being in the "help make Chrome more stable by running an ASAN build" group on each update. If that's not what you want, please run the "add" command again. If doing so does not result in they query command showing
    hint    REG_SZ    asan-optout
then there is something else on your computer that is interfering with ordinary registry operations performed by reg.exe.

Comment 25 by, Jan 6 2017

If I run 

reg query HKCU\Software\Google\Update\ClientState\{4EA16AC7-FD5A-47C3-875B-DBF4A2008C20}\cohort

right after running

reg add HKCU\Software\Google\Update\ClientState\{4EA16AC7-FD5A-47C3-875B-DBF4A2008C20}\cohort /v hint /d asan-optout /f

I get 

hint    REG_SZ    asan-optout

but if I apply an in-place update between running both commands I just get

hint    REG_SZ   

Ergo, it isn't a problem with my OS, PC, or reg.exe. Google Chrome is literally overwriting the opt-out setting every time it's updated. Can anyone fix this?

Comment 26 by, Jan 6 2017

Could you explain what you mean by "in-place update"? Are you re-running the installer from the download page, visiting chrome://help, or something else?

Comment 27 by, Jan 6 2017

Visiting chrome://help

Comment 28 by, Jan 9 2017

I don't have an explanation for this. I currently have asan-optout set, and it has not been cleared by the last week's worth of canary updates. Would you please re-run the "reg add" command, wait a few days to collect a few canary updates, then run the "reg query" command to see if the value has disappeared? Note that uninstalling Chrome Canary and re-installing from the download page (or a previously downloaded installer) is expected to clear the hint value.

Comment 29 by, Jan 9 2017

OK I'll try that.

Comment 30 by, Jan 19 2017

 Issue 681068  has been merged into this issue.

Comment 31 by, Apr 14 2017

Is there a reg edit to always get asan builds instead of the 1/20 chance?

Comment 32 by, Apr 18 2017

Yep, just run:
reg add HKCU\Software\Google\Update\ClientState\{4EA16AC7-FD5A-47C3-875B-DBF4A2008C20}\cohort /v hint /d asan-optin /f


Comment 33 Deleted

Comment 34 by, May 25 2017

 Issue 726174  has been merged into this issue.

Comment 35 by, May 31 2017

So my work PC just got pushed a 32-bit build, and the 64-bit installer download keeps failing. Thanks a lot for continuing to abuse your users, guys. This is such an incredibly *ed up policy. And no, registry opt-outs aren't the answer, users should NOT be pushed builds of a type they didn't install in the 1st place. 

I'm beginning to think this sis the result of some kind of bias against Windows users, since somehow we're the only ones cursed with this issue. Why not other OSes? Why are we singled out for this continued nonsense?

Comment 36 by, Jun 2 2017

Re: Comment 35 by judahric:

For a good insight into why users are randomly selected to run 32 bit builds see this article:

To me this is just a part of being on a "bleeding edge" developer channel and making a contribution. The 32 bit install is only for a limited time - as soon as the next higher level update to the 64 bit update is available it will be installed and you will be back on 64 bit. 

I run Canary on three (3) different Win 7 64 bit Pro & Enterprise instances. I have set the registry key to prevent the 32 bit selection on my somewhat under configured Corporate laptop - it really has bad performance issues with the 32 bit Canary. 

On the other instances if they are selected - I will can live with it till the next update to the 64 bit. I can tell by the sound of my fan right away if I have been selected - my home desktop has at least 4 Canary windows with 50 - 100 total tabs open. Excellent stress test till all the tabs finish loading.

This is all just part of being on a developer channel and trying to make a contribution. In no way do I consider it abuse. There is always the Beta & Stable channels available ...

Comment 37 by, Jun 26 2017

Yet another instance of a previously opted out 64-bit PC being pushed a broken 32-bit build smfh

Comment 38 by, Sep 11 2017

 Issue 763715  has been merged into this issue.

Comment 39 by, Sep 13 2017

 Issue 764639  has been merged into this issue.

Comment 40 by, Oct 12 2017

I am part of a game developers collaboration testing team, and I can tell you right now that chrome 32 bits on a 64 bits machine doesn't render. I fail to understand why you would claim to need to employ a mismatching update in search for bugs. OBVIOUSLY it will not work. It doesn't communicate well with my hardware and OS. I just uninstalled canary for the 5th time because of this bug. Gonna try the opt-out now - hoping it sticks.

Comment 41 by, Sep 27

 Issue 865041  has been merged into this issue.

Comment 42 by, Sep 27

@Comment 40: Exactly, right? BTW the same garbage just happened on Windows 10 1803 x64 machine. Google has nearly infinite testing infrastructure if they need to test 32-bit builds, so why push them on 64-bit users? 

64-bit testers should expect 64-bit builds, because the original installer literally says it's 64-bit. This is fraudulent at the very least.

Comment 43 by, Sep 27

We retired the ASAN channel for other reasons at the beginning of this year, so this is no longer happening.

Comment 44 by, Sep 27

@Comment 43: I appreciate that you did so, but I can certainly confirm that my Win64 Chrome was updated to 32-bit last week. That said, I hadn't done a manual in-place (i.e. not uninstalling 1st) since reinstall since last year, and there were 2 Windows 10 feature updates between my last post to this thread and now.

I did an in-place 64-bit reinstall this morning on the affected machine that paved over the 32-bit build. Hopefully that fixes things permanently.

Again, thanks for retiring that channel. It's very much appreciated.

Comment 45 by, Sep 27

I spoke slightly too soon, apparently we *are* still shipping a build that could downgrade an installation to 32-bit, but it is most definitely not an ASAN build as that has been retired. I'm finding out whether or not this is accidental or on purpose and will follow up!

Comment 46 by, Oct 5

Happened again today to the same machine I mentioned in Comment 44. It definitely hasn't stopped or abated in any way. SMH ... this is just ridiculous.

Comment 47 by, Oct 10

It is another diagnostic build, but not one that has any particular need to be in 32-bit. The owner has been made aware of the problem and a bug has been filed to fix it.

Comment 48 by, Oct 11

OK thanks, hopefully that resolves the issue.

Comment 49 by, Nov 9

Happened again literally just now.

Comment 50 by, Feb 17 (6 days ago)

Happened here too.

Comment 51 by, Feb 17 (6 days ago)

I've had it happen again since my last message, but it fixed itself and
reverted to a 64-bit build within a day or so.

On Sun, Feb 17, 2019, 08:11 mwrobe… via monorail < wrote:

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