These builders have the similar symptoms:

https://build.chromium.org/p/chromium.webkit/builders/WebKit%20Win%20x64%20Builder%20%28dbg%29/builds/108387
https://build.chromium.org/p/chromium.webkit/builders/WebKit%20Win7%20(dbg)

WebKit Win 7 (dbg)

https://luci-logdog.appspot.com/v/?s=chromium%2Fbb%2Fchromium.webkit%2FWebKit_Win7__dbg_%2F9767%2F%2B%2Frecipes%2Fsteps%2Fblink_heap_unittests%2F0%2Fstdout

+---------------------------------------------------------------------------------+
| End of shard 0  Pending: 2.8s  Duration: 1.5s  Bot: vm367-m4  Exit: -1073741701 |
+---------------------------------------------------------------------------------+

Exit code is -1073741701, which is 0xC000007B, which is Bad Image??
binary broken?

reverted the culprit

I verified locally that this is caused by https://chromium-review.googlesource.com/c/497830/

Thanks, seemed to work. Closing.

Troopers, sorry for false alerm!

I might be missing something but as sheriff I am still being notified in SOM about this issue.

https://uberchromegw.corp.google.com/i/chromium.win/waterfall?show=Win7%20Tests%20(dbg)(1)

Should it really be marked as fixed?

Looks fixed to me?

These are failing again and I don't see any test failures. There are just lots of the following messages in the output from app_shell_unittests, browser_tests, and others:

shard 0 test output missing
Task ran but no result was found: shard 0 test output was missing
some shards did not complete: 0

Latest is at https://build.chromium.org/p/chromium.win/builders/Win7%20Tests%20%28dbg%29%281%29/builds/59894

OK thanks for the link. Looks like it's the same issue, i.e. one or more
shared libraries missing from the isolate.

I'll revert again...

Since this is being handled by Sheriffs and is not an infrastructure issue, I'm going to remove the troopers label. Feel free to re-add if you think it's necessary for troopers to be involved!

rockot: can you add a link to the revert here when you get a chance?

Sure, it's https://crrev.com/bcce6e40e5649f1d5d2485a49c91212e97e3851a

Issue 721919 has been merged into this issue.

Looks good after the last revert.

Fun fact for posterity: This was not caused by a missing DLL, but rather was the result of having an empty DLL (a component target with a single empty source file) in the dependency tree. Apparently Windows is not happy with that!

I was able to repro with a local swarming run and have verified my fix, so I'm going to reland one more time and keep an eye on these bots.