@Sam: Thanks for filing the issue.

Could you please provide sample extension to test the issue

That will help us in further triaging of the issue.

Thanks,

I've attached a sample extension.

I've further narrowed it down to not occurring when you only have one window open. If you open a second, you get 'other' instead.

## Steps to reproduce

1. Open new browser session with one window.
2. Install sample extension.
3. Open background page for extension.
4. open a new tab, go to google.com.
5. Press the browser action (the D)

### Expected

No errors in console

### Actual

No errors in console


6. Open a new window.
7. Navigate to google.com
8. Press the browser action again.


### Expected

Same result as (5), no error

### Actual

_generated_background_page.html:1 Uncaught (in promise) no targets found



## Notes

Please let me know if you need any more info. The impact is that you cannot tell if a debugger is already attached to a tab before attempting to attach/detach from it.

Deleted: debugger_example.zip 1.2 KB

debugger_example.zip 1.2 KB Download

Thank you for providing more feedback. Adding requester "sandeepkumars@chromium.org" to the cc list and removing "Needs-Feedback" label.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

@Sam: Could you please find the attached screenshot and let us know, that's the error you're talking about?

If possible please attach a expected screenshot from your end.

That will help us in further triaging of this issue.

Thanks,

Deleted: Screen Shot 2017-05-09 at 5.06.56 PM.png 145 KB

	Screen Shot 2017-05-09 at 5.06.56 PM.png 145 KB View Download

@sandeepkumars that is not the bug, that is the expected behavior. I've attached a video with steps to reproduce, but basically you should see an error in the console with 'Uncaught (in promise) no targets found'

## Simplified steps to reproduce (as shown in the video)

1. Open Chrome (59)
2. Open google.com (or any page) in the first tab
3. Open chrome://extensions in the second tab
4. open the background devtools page for the extension
5. click the browser action in the google.com tab

### Expected

No error

### Actual

No error

6. Quit and reopen Chrome.
7. Open chrome://extensions in first tab
8. Open background page for extension
9. Open google.com in second tab
10. Click browser action for test extension

### Expected
Same behavior as above, no error

### Actual

Error in the console: 'Uncaught (in promise) no targets found'

Deleted: chrome-debugger-getTargets-bug.mp4 3.6 MB

	chrome-debugger-getTargets-bug.mp4 3.6 MB View Download

Thank you for providing more feedback. Adding requester "sandeepkumars@chromium.org" to the cc list and removing "Needs-Feedback" label.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Able to reproduce the issue using latest Chrome version 59.0.3071.71 on Mac 10.12.4 Issue is not seen in Windows and Linux

Below is the bisect information
==============================

Using the per-revision bisect providing the bisect results,
Good Build: 59.0.3067.0 (Revision: 463157)
Bad Build: 59.0.3068.1 (Revision: 463474)

You are probably looking for a change made after 463317 (known good), but no later than 463318 (first known bad).

CHANGELOG URL:
https://chromium.googlesource.com/chromium/src/+log/8088cc1ba912e866ea7c5daef7a7b4beba74525c..e63206f4ef0c18bca991534852acd0193a2de94a

@arthursonzogni: Could you please look into the issue, pardon me if it has nothing to do with your changes and if possible please assign it to concern owner.

Review URL:  https://codereview.chromium.org/2798583002

Adding Release Block Stable as this is a recent regression, please undo if someone feel otherwise.

Thank You.

I tried your repro steps, but the "Inspect view: background page" is not visible to me. I have checked the manifest.json, it looks correct AFAIK.

I am using a Linux desktop, so even if I was not blocked at this step, I would not be able to reproduce the issue since it only affect Mac users.

I would be very surprise that my patch causes the issue. The patch affects only the Web UI of the print preview.
+CC thestig@ who reviewed this CL.

lazyboy@: would you mind helping me triaging the issue?

+devlin

I also tested ToT on Linux and didn't run into any problems. I can try Windows later but I don't have a Mac at the moment. We should also double check the bisect. I'm surprised r463318 would trigger this.

I've tried mac 59.0.3071.71, couldn't repro this with the sample extension in comment #3 either. The tab info appears fine.

@sam, does this reproduce on 59.0.3071.71?

@lazyboy looks good on Mac 59.0.3071.71.

Thanks @sam, given that this broke and fixed in 59, I'll close this one.
(Although it would be interesting to know when/what broke)