Mac web_tool_tests has become very flaky #123018
Description
Failures are in hot restart tests. In the past 6 flakes, there have been failures in two different unit tests. See:
https://ci.chromium.org/ui/p/flutter/builders/prod/Mac%20web_tool_tests/11270/overview and
https://ci.chromium.org/ui/p/flutter/builders/prod/Mac%20web_tool_tests/11260/overview
The failures look similar though. From the first link:
[ +53 ms] DwdsVmClient: Successful hot restart
[ +2 ms] ChromeProxyService: Caching package:flutter/src/widgets/widget_inspector.dart in expression compiler worker
[ ] DevHandler: VmService proxy responded with an error:
{jsonrpc: 2.0, id: 15, error: {code: -32603, message: getIsolate: [Sentinel kind: Collected, valueAsString: Unrecognized isolateId: 1] from getIsolate(), data: {details: #0 ChromeProxyService._throwSentinel (package:dwds/src/services/chrome_proxy_service.dart:1154:5)
#1 ChromeProxyService._checkIsolate (package:dwds/src/services/chrome_proxy_service.dart:1146:7)
#2 ChromeProxyService.getIsolate.<anonymous closure> (package:dwds/src/services/chrome_proxy_service.dart:569:7)
<asynchronous suspension>
#3 StackZoneSpecification._registerUnaryCallback.<anonymous closure> (package:stack_trace/src/stack_zone_specification.dart:124:15)
<asynchronous suspension>
}}}
From the second link:
[ +49 ms] DwdsVmClient: Successful hot restart
[ +1 ms] ChromeProxyService: Caching package:flutter/src/widgets/widget_inspector.dart in expression compiler worker
[ ] DevHandler: VmService proxy responded with an error:
{jsonrpc: 2.0, id: 15, error: {code: -32603, message: getIsolate: [Sentinel kind: Collected, valueAsString: Unrecognized isolateId: 1] from getIsolate(), data: {details: #0 ChromeProxyService._throwSentinel (package:dwds/src/services/chrome_proxy_service.dart:1154:5)
#1 ChromeProxyService._checkIsolate (package:dwds/src/services/chrome_proxy_service.dart:1146:7)
#2 ChromeProxyService.getIsolate.<anonymous closure> (package:dwds/src/services/chrome_proxy_service.dart:569:7)
<asynchronous suspension>
#3 StackZoneSpecification._registerUnaryCallback.<anonymous closure> (package:stack_trace/src/stack_zone_specification.dart:124:15)
<asynchronous suspension>
}}}