Coverlet fails to write coverage with file locked error

[abe545]

So this is a bit odd, but it only happens during our CI (and it is intermittent). We're using v1.2 of the vstest collector.

The error we get is this:

Data collector 'XPlat code coverage' message: [coverlet]Coverlet.Collector.Utilities.CoverletDataCollectorException: CoverletCoverageDataCollector: Failed to get coverage result
 ---> System.IO.IOException: The process cannot access the file '/tmp/MySourceProject_8b9f64e1-2aa6-4144-aece-e1ec4323d842' because it is being used by another process.
   at System.IO.FileStream.Init(FileMode mode, FileShare share, String originalPath)
   at System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, FileOptions options)
   at System.IO.FileStream..ctor(String path, FileMode mode)
   at Coverlet.Core.Helpers.FileSystem.NewFileStream(String path, FileMode mode) in D:\git\coverletToRelease\src\coverlet.core\Helpers\FileSystem.cs:line 43
   at Coverlet.Core.Coverage.CalculateCoverage() in D:\git\coverletToRelease\src\coverlet.core\Coverage.cs:line 352
   at Coverlet.Core.Coverage.GetCoverageResult() in D:\git\coverletToRelease\src\coverlet.core\Coverage.cs:line 137
   at Coverlet.Collector.DataCollection.CoverageWrapper.GetCoverageResult(Coverage coverage) in D:\git\coverletToRelease\src\coverlet.collector\DataCollection\CoverageWrapper.cs:line 44
   at Coverlet.Collector.DataCollection.CoverageManager.GetCoverageResult() in D:\git\coverletToRelease\src\coverlet.collector\DataCollection\CoverageManager.cs:line 91
   --- End of inner exception stack trace ---
   at Coverlet.Collector.DataCollection.CoverageManager.GetCoverageResult() in D:\git\coverletToRelease\src\coverlet.collector\DataCollection\CoverageManager.cs:line 96
   at Coverlet.Collector.DataCollection.CoverletCoverageCollector.OnSessionEnd(Object sender, SessionEndEventArgs e) in D:\git\coverletToRelease\src\coverlet.collector\DataCollection\CoverletCoverageCollector.cs:line 148.

What is strange is that after this error message, we see the last test case complete (we use the normal logging verbosity so we see every test case printed). We're using .net core 3.1, and xunit 2.4.1 if it matters (we use a xunit collection fixture too). It appears that the collection fixture is disposed before the last test's results are printed whether coverlet succeeds or not, so I'm thinking the last test being printed out after the coverlet error is not an indication that it is actually running after coverlet is blocked.

Some other interesting info about our builds: It is in a docker container, with the test results directory mounted on a volume, so I can't imagine another process is stepping on any file being used here. We pass a filter into dotnet test because we have a number of expensive tests that we run in parallel by running multiple docker containers with different filters simultaneously.

When running 16.4.0 of the test sdk, we'd often see the error manifest as:

Data collector 'XPlat code coverage' message: [coverlet]Coverlet.Collector.Utilities.CoverletDataCollectorException: CoverletCoverageDataCollector: Failed to get coverage result
 ---> System.IO.EndOfStreamException: Unable to read beyond the end of the stream.
   at System.IO.BinaryReader.InternalRead(Int32 numBytes)
   at Coverlet.Core.Coverage.CalculateCoverage() in D:\git\coverletToRelease\src\coverlet.core\Coverage.cs:line 363
   at Coverlet.Core.Coverage.GetCoverageResult() in D:\git\coverletToRelease\src\coverlet.core\Coverage.cs:line 137
   at Coverlet.Collector.DataCollection.CoverageWrapper.GetCoverageResult(Coverage coverage) in D:\git\coverletToRelease\src\coverlet.collector\DataCollection\CoverageWrapper.cs:line 44
   at Coverlet.Collector.DataCollection.CoverageManager.GetCoverageResult() in D:\git\coverletToRelease\src\coverlet.collector\DataCollection\CoverageManager.cs:line 91
   --- End of inner exception stack trace ---
   at Coverlet.Collector.DataCollection.CoverageManager.GetCoverageResult() in D:\git\coverletToRelease\src\coverlet.collector\DataCollection\CoverageManager.cs:line 96
   at Coverlet.Collector.DataCollection.CoverletCoverageCollector.OnSessionEnd(Object sender, SessionEndEventArgs e) in D:\git\coverletToRelease\src\coverlet.collector\DataCollection\CoverletCoverageCollector.cs:line 148.

But I'm only seeing the first error I posted with 16.5.0.

[MarcoRossignoli]

Hi Abraham, some notes

When running 16.4.0 of the test sdk, we'd often see the error manifest as:

It's ok and expected, until sdk 16.5.0 there was a bug inside vstest and coverlet collection greater than 1.0.0 weren't loaded https://github.com/tonerdo/coverlet/blob/master/Documentation/KnowIssues.md#2-upgrade-coverletcollector-to-version--100
So here you're hitting the above issue.

The process cannot access the file

Are you running test on solution file(or repo root) or are you running dotnet test on every test project?If you're running from sln can you try with one dotnet test for every test csproj?
I saw this issue another time on big solutions where for some reason parallel tests locked hit file, as if the same instrumented lib was used in different process and so same file is used https://github.com/tonerdo/coverlet/blob/master/src/coverlet.core/Instrumentation/Instrumenter.cs#L239

[abe545]

I'm running it on the csproj file directly with this command:

dotnet test ./MyTestProject/MyTestProject.csproj --configuration Release --no-build -v n --collect:"XPlat Code Coverage" --settings coverlet.runsettings --filter "Feature=Foo"

I then have various test classes that use xunit traits:

[Trait("Feature", "Foo")]
public class SomeFeature { ... }

Also, I forgot to mention, I pass it this runsettings file:

<?xml version="1.0" encoding="utf-8" ?>
<RunSettings>
  <DataCollectionRunSettings>
    <DataCollectors>
      <DataCollector friendlyName="XPlat code coverage">
        <Configuration>
          <Format>lcov</Format>
          <Exclude>[xunit*]*</Exclude>
          <ExcludeByFile>/app/gen/Namely.*.Grpc/*</ExcludeByFile>
        </Configuration>
      </DataCollector>
    </DataCollectors>
  </DataCollectionRunSettings>
</RunSettings>

[abe545]

I'm currently trying to create a repro case, but am struggling. One thing I'm noticing in my real project is that this is logged before the last test's result (whether coverlet fails or not):

[xUnit.net 00:06:54.88]   Finished:    MyTestProject

Update
This strange ordering of the finished message doesn't always happen after I updated my base docker images to the latest 3.1.2 image 🤷‍♂

[abe545]

And it gets slightly more frustrating: I witnessed a test run fail to generate coverage with the same error on one of my projects that does not use filters or xunit fixtures/collections, but otherwise the setup is identical: running in docker, using latest coverlet + .net sdk + xunit.

[abe545]

So interestingly, I'm now consistently getting the failure for a specific set of filters - If I run this locally within a docker-compose, I get the same issue. I thought it might be the parallel containers' volume mounts somehow stepping on each other, but I see the error even when this is the only container executing. I'll continue to try to repro this in a shareable manner.

[MarcoRossignoli]

Does it happen out of container?

[MarcoRossignoli]

Another test we can do, can you generate logs using --diag:log.txt https://github.com/tonerdo/coverlet/blob/master/Documentation/Troubleshooting.md#collectors-integration

[abe545]

I haven't witnessed it outside the container. I'll generate the logs and report back.

[abe545]

@MarcoRossignoli thank you for your help on this! I think I found the culprit:

 System.IO.IOException : The configured user limit (128) on the number of inotify instances has been reached, or the per-process limit on the number of open file descriptors has been reached.

So we were using the default asp.net host (and running tests against the test server). This by default adds 2 watched json files for the application configuration. By taking full control of the host being built, I was able to at least intermittently get the coverage working again.

This is seemingly a race condition between xunit parallelized collections - on my PC that I've given more resources to docker, I was getting test failures with the above error also. So it seems like the file handles opened by asp.net were hitting a limit, and we were lucky it wasn't failing tests also in our CI.

[MarcoRossignoli]

Was on logs that message?

[abe545]

They were... but sadly I hard deleted the logs as I was trying to investigate my issue.
I've updated how we create the config to not watch the json files, and I'm still seeing the original hits file error in another filtered project, but not the user limit error.

[MarcoRossignoli]

but not the user limit error.

Some other strange infos from logs?

[abe545]

I didn't see anything obviously wrong, but here is the the collector logs:

TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:53.565, 40768041605418, datacollector.dll, DataCollectorMain.Run: Starting data collector run with args: --port,46037,--parentprocessid,48,--diag,/app/coverletlogs/log-paychecks.datacollector.20-02-20_06-07-53_48147_4.txt,--tracelevel,4
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:53.577, 40768047486944, datacollector.dll, DataCollector: Monitoring parent process with id: '48'
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:53.599, 40768068596128, datacollector.dll, Trying to connect to server on socket : 127.0.0.1:46037 
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:53.612, 40768081659720, datacollector.dll, SocketCommunicationManager : SetupClientAsync : Attempting to connect to the server.
TpTrace Information: 0 : 61, 5, 2020/02/20, 06:07:53.626, 40768096147895, datacollector.dll, Connected to the server successfully 
TpTrace Information: 0 : 61, 5, 2020/02/20, 06:07:53.627, 40768096890304, datacollector.dll, Using the buffer size of 16384 bytes
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:53.714, 40768184173607, datacollector.dll, DataCollector: Start Request Processing.
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:53.720, 40768190012990, datacollector.dll, DataCollectionRequestHandler.ProcessRequests : Datacollector received message: (DataCollection.BeforeTestRunStart) -> {
  "SettingsXml": "<RunSettings><DataCollectionRunSettings><DataCollectors><DataCollector friendlyName=\"XPlat code coverage\" enabled=\"True\"><Configuration><Format>lcov</Format><Exclude>[xunit*]*</Exclude><ExcludeByFile>/app/gen/Namely.*.Grpc/*</ExcludeByFile></Configuration></DataCollector></DataCollectors></DataCollectionRunSettings><RunSettingsDirectory>/app/test</RunSettingsDirectory><RunConfiguration><ResultsDirectory>/coverage/paychecks</ResultsDirectory><TargetPlatform>X64</TargetPlatform><TargetFrameworkVersion>.NETCoreApp,Version=v3.1</TargetFrameworkVersion><TestAdaptersPaths>/root/.nuget/packages/coverlet.collector/1.2.0/build/netstandard1.0/;/root/.nuget/packages/microsoft.codecoverage/16.5.0/build/netstandard1.0/;/usr/share/dotnet/sdk/3.1.102/Extensions</TestAdaptersPaths><DesignMode>False</DesignMode><CollectSourceInformation>False</CollectSourceInformation></RunConfiguration><InProcDataCollectionRunSettings><InProcDataCollectors><InProcDataCollector assemblyQualifiedName=\"Coverlet.Collector.DataCollection.CoverletInProcDataCollector, coverlet.collector, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null\" friendlyName=\"XPlat Code Coverage\" enabled=\"True\" codebase=\"coverlet.collector.dll\" /></InProcDataCollectors></InProcDataCollectionRunSettings><LoggerRunSettings><Loggers><Logger friendlyName=\"Console\" assemblyQualifiedName=\"Microsoft.VisualStudio.TestPlatform.CommandLine.Internal.ConsoleLogger, vstest.console, Version=15.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a\" codeBase=\"/usr/share/dotnet/sdk/3.1.102/vstest.console.dll\" enabled=\"True\"><Configuration><Verbosity>normal</Verbosity></Configuration></Logger></Loggers></LoggerRunSettings></RunSettings>",
  "Sources": [
    "/app/test/PayrollSteps.Api.Test/bin/Release/netcoreapp3.1/PayrollSteps.Api.Test.dll"
  ]
}
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:53.835, 40768304923678, datacollector.dll, TestPluginCache: Update extensions started. Skip filter = False
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:53.837, 40768306755811, datacollector.dll, TestPluginCache: Using directories for assembly resolution '/root/.nuget/packages/coverlet.collector/1.2.0/build/netstandard1.0,/root/.nuget/packages/microsoft.codecoverage/16.5.0/build/netstandard1.0,/usr/share/dotnet/sdk/3.1.102/Extensions'.
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:53.838, 40768307509053, datacollector.dll, TestPluginCache: Updated the available extensions to '/root/.nuget/packages/coverlet.collector/1.2.0/build/netstandard1.0/coverlet.collector.dll,/root/.nuget/packages/microsoft.codecoverage/16.5.0/build/netstandard1.0/Microsoft.VisualStudio.TraceDataCollector.dll,/usr/share/dotnet/sdk/3.1.102/Extensions/Microsoft.TestPlatform.Extensions.BlameDataCollector.dll,/usr/share/dotnet/sdk/3.1.102/Extensions/Microsoft.TestPlatform.Extensions.EventLogCollector.dll'.
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:53.857, 40768327016204, datacollector.dll, TestPluginCache.DiscoverTestExtensions: finding test extensions in assemblies endswith: Collector.dll TPluginInfo: Microsoft.VisualStudio.TestPlatform.Common.DataCollector.DataCollectorConfig TExtension: Microsoft.VisualStudio.TestPlatform.ObjectModel.DataCollection.DataCollector
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:53.858, 40768328076029, datacollector.dll, TestPluginCache.GetExtensionPaths: Filtered extension paths: /root/.nuget/packages/coverlet.collector/1.2.0/build/netstandard1.0/coverlet.collector.dll
/root/.nuget/packages/microsoft.codecoverage/16.5.0/build/netstandard1.0/Microsoft.VisualStudio.TraceDataCollector.dll
/usr/share/dotnet/sdk/3.1.102/Extensions/Microsoft.TestPlatform.Extensions.BlameDataCollector.dll
/usr/share/dotnet/sdk/3.1.102/Extensions/Microsoft.TestPlatform.Extensions.EventLogCollector.dll
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:53.859, 40768328734479, datacollector.dll, TestPluginCache.GetExtensionPaths: Added default extension paths: 
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:53.860, 40768329604070, datacollector.dll, TestPluginCache.GetExtensionPaths: Added unfilterableExtensionPaths: 
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:53.861, 40768331047070, datacollector.dll, AssemblyResolver.ctor: Creating AssemblyResolver with searchDirectories /root/.nuget/packages/coverlet.collector/1.2.0/build/netstandard1.0,/root/.nuget/packages/microsoft.codecoverage/16.5.0/build/netstandard1.0,/usr/share/dotnet/sdk/3.1.102/Extensions,/usr/share/dotnet/sdk/3.1.102
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:53.863, 40768333067704, datacollector.dll, TestPluginCache.DiscoverTestExtensions: Discovering the extensions using extension path.
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:53.864, 40768333983879, datacollector.dll, TestPluginCache.GetExtensionPaths: Filtered extension paths: /root/.nuget/packages/coverlet.collector/1.2.0/build/netstandard1.0/coverlet.collector.dll
/root/.nuget/packages/microsoft.codecoverage/16.5.0/build/netstandard1.0/Microsoft.VisualStudio.TraceDataCollector.dll
/usr/share/dotnet/sdk/3.1.102/Extensions/Microsoft.TestPlatform.Extensions.BlameDataCollector.dll
/usr/share/dotnet/sdk/3.1.102/Extensions/Microsoft.TestPlatform.Extensions.EventLogCollector.dll
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:53.865, 40768334644496, datacollector.dll, TestPluginCache.GetExtensionPaths: Added default extension paths: 
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:53.865, 40768335406837, datacollector.dll, TestPluginCache.GetExtensionPaths: Added unfilterableExtensionPaths: 
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:53.866, 40768336256062, datacollector.dll, TestPluginCache.DiscoverTestExtensions: Discovering the extensions using allExtensionPaths: /root/.nuget/packages/coverlet.collector/1.2.0/build/netstandard1.0/coverlet.collector.dll
/root/.nuget/packages/microsoft.codecoverage/16.5.0/build/netstandard1.0/Microsoft.VisualStudio.TraceDataCollector.dll
/usr/share/dotnet/sdk/3.1.102/Extensions/Microsoft.TestPlatform.Extensions.BlameDataCollector.dll
/usr/share/dotnet/sdk/3.1.102/Extensions/Microsoft.TestPlatform.Extensions.EventLogCollector.dll
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:53.867, 40768337212646, datacollector.dll, AssemblyResolver.AddSearchDirectories: Adding more searchDirectories /root/.nuget/packages/coverlet.collector/1.2.0/build/netstandard1.0,/usr/share/dotnet/sdk/3.1.102
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:53.868, 40768337980729, datacollector.dll, AssemblyResolver.AddSearchDirectories: Adding more searchDirectories /root/.nuget/packages/microsoft.codecoverage/16.5.0/build/netstandard1.0,/usr/share/dotnet/sdk/3.1.102
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:53.869, 40768338746537, datacollector.dll, AssemblyResolver.AddSearchDirectories: Adding more searchDirectories /usr/share/dotnet/sdk/3.1.102/Extensions,/usr/share/dotnet/sdk/3.1.102
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:53.870, 40768339597929, datacollector.dll, AssemblyResolver.AddSearchDirectories: Adding more searchDirectories /usr/share/dotnet/sdk/3.1.102/Extensions,/usr/share/dotnet/sdk/3.1.102
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:53.871, 40768340873554, datacollector.dll, AssemblyResolver.OnResolve: coverlet.collector: Resolving assembly.
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:53.872, 40768342193487, datacollector.dll, AssemblyResolver.OnResolve: Resolved assembly: coverlet.collector, from path: /root/.nuget/packages/coverlet.collector/1.2.0/build/netstandard1.0/coverlet.collector.dll
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:53.873, 40768343483413, datacollector.dll, AssemblyResolver.OnResolve: coverlet.core: Resolving assembly.
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:53.875, 40768344691221, datacollector.dll, AssemblyResolver.OnResolve: Resolved assembly: coverlet.core, from path: /root/.nuget/packages/coverlet.collector/1.2.0/build/netstandard1.0/coverlet.core.dll
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:53.877, 40768347228604, datacollector.dll, AssemblyResolver.OnResolve: Microsoft.VisualStudio.TraceDataCollector: Resolving assembly.
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:53.878, 40768348475521, datacollector.dll, AssemblyResolver.OnResolve: Resolved assembly: Microsoft.VisualStudio.TraceDataCollector, from path: /root/.nuget/packages/microsoft.codecoverage/16.5.0/build/netstandard1.0/Microsoft.VisualStudio.TraceDataCollector.dll
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:53.880, 40768350296171, datacollector.dll, AssemblyResolver.OnResolve: Microsoft.TestPlatform.Extensions.BlameDataCollector: Resolving assembly.
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:53.882, 40768351495638, datacollector.dll, AssemblyResolver.OnResolve: Resolved assembly: Microsoft.TestPlatform.Extensions.BlameDataCollector, from path: /usr/share/dotnet/sdk/3.1.102/Extensions/Microsoft.TestPlatform.Extensions.BlameDataCollector.dll
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:53.883, 40768352822613, datacollector.dll, AssemblyResolver.OnResolve: Microsoft.TestPlatform.Extensions.EventLogCollector: Resolving assembly.
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:53.884, 40768354027821, datacollector.dll, AssemblyResolver.OnResolve: Resolved assembly: Microsoft.TestPlatform.Extensions.EventLogCollector, from path: /usr/share/dotnet/sdk/3.1.102/Extensions/Microsoft.TestPlatform.Extensions.EventLogCollector.dll
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:53.886, 40768356347021, datacollector.dll, TestPluginCache: Discovered the extensions using extension path '/root/.nuget/packages/coverlet.collector/1.2.0/build/netstandard1.0/coverlet.collector.dll,/root/.nuget/packages/microsoft.codecoverage/16.5.0/build/netstandard1.0/Microsoft.VisualStudio.TraceDataCollector.dll,/usr/share/dotnet/sdk/3.1.102/Extensions/Microsoft.TestPlatform.Extensions.BlameDataCollector.dll,/usr/share/dotnet/sdk/3.1.102/Extensions/Microsoft.TestPlatform.Extensions.EventLogCollector.dll'.
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:53.887, 40768357329930, datacollector.dll, TestPluginCache: Discoverers are ''.
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:53.888, 40768358165830, datacollector.dll, TestPluginCache: Executors are ''.
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:53.889, 40768359064021, datacollector.dll, TestPluginCache: Setting providers are ''.
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:53.890, 40768360024830, datacollector.dll, TestPluginCache: Loggers are ''.
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:53.893, 40768362841822, datacollector.dll, TestPluginManager.CreateTestExtension: Attempting to load test extension: Coverlet.Collector.DataCollection.CoverletCoverageCollector
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:53.898, 40768367567863, datacollector.dll, [coverlet]Initializing CoverletCoverageDataCollector with configuration: '<Configuration><Format>lcov</Format><Exclude>[xunit*]*</Exclude><ExcludeByFile>/app/gen/Namely.*.Grpc/*</ExcludeByFile><Framework>.NETCoreApp,Version=v3.1</Framework></Configuration>'
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:53.900, 40768369712430, datacollector.dll, [coverlet]CoverletCoverageDataCollector: SessionStart received
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:53.901, 40768371128239, datacollector.dll, [coverlet]CoverletCoverageDataCollector: TestModules: '/app/test/PayrollSteps.Api.Test/bin/Release/netcoreapp3.1/PayrollSteps.Api.Test.dll'
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:53.906, 40768375639455, datacollector.dll, [coverlet]CoverletCoverageDataCollector: Initializing coverlet process with settings: "TestModule: '/app/test/PayrollSteps.Api.Test/bin/Release/netcoreapp3.1/PayrollSteps.Api.Test.dll', IncludeFilters: '', IncludeDirectories: '', ExcludeFilters: '[coverlet.*]*,[xunit*]*', ExcludeSourceFiles: '/app/gen/Namely.*.Grpc/*', ExcludeAttributes: '', MergeWith: '', UseSourceLink: 'False'SingleHit: 'False'IncludeTestAssembly: 'False'"
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:53.909, 40768379089980, datacollector.dll, AssemblyResolver.OnResolve: Microsoft.Extensions.DependencyInjection: Resolving assembly.
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:53.910, 40768380379581, datacollector.dll, AssemblyResolver.OnResolve: Resolved assembly: Microsoft.Extensions.DependencyInjection, from path: /root/.nuget/packages/coverlet.collector/1.2.0/build/netstandard1.0/Microsoft.Extensions.DependencyInjection.dll
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:53.911, 40768381196522, datacollector.dll, AssemblyResolver.OnResolve: Microsoft.Extensions.DependencyInjection.Abstractions: Resolving assembly.
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:53.912, 40768382218322, datacollector.dll, AssemblyResolver.OnResolve: Resolved assembly: Microsoft.Extensions.DependencyInjection.Abstractions, from path: /root/.nuget/packages/coverlet.collector/1.2.0/build/netstandard1.0/Microsoft.Extensions.DependencyInjection.Abstractions.dll
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:53.958, 40768428203007, datacollector.dll, [coverlet]Excluded module filter '[coverlet.*]*'
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:53.959, 40768429211157, datacollector.dll, [coverlet]Excluded module filter '[xunit*]*'
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:53.960, 40768430102416, datacollector.dll, [coverlet]Excluded source files filter '/app/gen/Namely.*.Grpc/*'
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:53.971, 40768441266058, datacollector.dll, [coverlet]Excluded module: '/app/test/PayrollSteps.Api.Test/bin/Release/netcoreapp3.1/xunit.assert.dll'
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:53.973, 40768443237508, datacollector.dll, AssemblyResolver.OnResolve: Microsoft.Extensions.FileSystemGlobbing: Resolving assembly.
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:53.975, 40768444569466, datacollector.dll, AssemblyResolver.OnResolve: Resolved assembly: Microsoft.Extensions.FileSystemGlobbing, from path: /root/.nuget/packages/coverlet.collector/1.2.0/build/netstandard1.0/Microsoft.Extensions.FileSystemGlobbing.dll
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:53.999, 40768468916409, datacollector.dll, [coverlet]Unable to instrument module: /app/test/PayrollSteps.Api.Test/bin/Release/netcoreapp3.1/Humanizer.dll, embedded pdb without local source files, [d:\a\1\s\src\Humanizer\obj\Release\netstandard2.0\Humanizer.Version.cs]
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:54.000, 40768470452792, datacollector.dll, [coverlet]Excluded module: '/app/test/PayrollSteps.Api.Test/bin/Release/netcoreapp3.1/xunit.runner.utility.netcoreapp10.dll'
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:54.002, 40768471754309, datacollector.dll, [coverlet]Excluded module: '/app/test/PayrollSteps.Api.Test/bin/Release/netcoreapp3.1/xunit.abstractions.dll'
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:54.011, 40768481053643, datacollector.dll, AssemblyResolver.OnResolve: Mono.Cecil: Resolving assembly.
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:54.012, 40768482416801, datacollector.dll, AssemblyResolver.OnResolve: Resolved assembly: Mono.Cecil, from path: /root/.nuget/packages/coverlet.collector/1.2.0/build/netstandard1.0/Mono.Cecil.dll
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:54.033, 40768503237277, datacollector.dll, AssemblyResolver.OnResolve: Microsoft.Extensions.DependencyModel: Resolving assembly.
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:54.035, 40768504833135, datacollector.dll, AssemblyResolver.OnResolve: Resolved assembly: Microsoft.Extensions.DependencyModel, from path: /root/.nuget/packages/coverlet.collector/1.2.0/build/netstandard1.0/Microsoft.Extensions.DependencyModel.dll
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:54.143, 40768613189439, datacollector.dll, AssemblyResolver.OnResolve: Mono.Cecil.Rocks: Resolving assembly.
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:54.145, 40768614820397, datacollector.dll, AssemblyResolver.OnResolve: Resolved assembly: Mono.Cecil.Rocks, from path: /root/.nuget/packages/coverlet.collector/1.2.0/build/netstandard1.0/Mono.Cecil.Rocks.dll
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:56.165, 40770635274945, datacollector.dll, [coverlet]Excluded source file: '/app/gen/Namely.Uploads.Grpc/ServiceGrpc.cs'
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:56.167, 40770636896370, datacollector.dll, [coverlet]Excluded source file: '/app/gen/Namely.TaxParams.Grpc/TaxParamsGrpc.cs'
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:56.167, 40770637483320, datacollector.dll, [coverlet]Excluded source file: '/app/gen/Namely.Releaseflags.Grpc/ServiceGrpc.cs'
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:56.168, 40770638125412, datacollector.dll, [coverlet]Excluded source file: '/app/gen/Namely.Proration.Grpc/ServiceGrpc.cs'
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:56.169, 40770638624287, datacollector.dll, [coverlet]Excluded source file: '/app/gen/Namely.PdfFormGeneration.Grpc/PdfFormGenerationGrpc.cs'
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:56.169, 40770639344921, datacollector.dll, [coverlet]Excluded source file: '/app/gen/Namely.PayrollProcessingDispatcher.Grpc/PayrollProcessingDispatcherGrpc.cs'
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:56.170, 40770639964479, datacollector.dll, [coverlet]Excluded source file: '/app/gen/Namely.Payroll.Grpc/ServiceGrpc.cs'
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:56.171, 40770640594329, datacollector.dll, [coverlet]Excluded source file: '/app/gen/Namely.Hcm.Grpc/ServiceGrpc.cs'
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:56.171, 40770641371621, datacollector.dll, [coverlet]Excluded source file: '/app/gen/Namely.Employment.Grpc/EmploymentReaderServiceGrpc.cs'
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:56.172, 40770641979479, datacollector.dll, [coverlet]Excluded source file: '/app/gen/Namely.Employment.Grpc/EmploymentWriterServiceGrpc.cs'
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:56.173, 40770642509229, datacollector.dll, [coverlet]Excluded source file: '/app/gen/Namely.Compensation.Grpc/ServiceGrpc.cs'
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:56.173, 40770643196062, datacollector.dll, [coverlet]Excluded source file: '/app/gen/Namely.Companies.Grpc/ServiceGrpc.cs'
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:56.174, 40770643755496, datacollector.dll, [coverlet]Excluded source file: '/app/gen/Namely.AddressValidator.Grpc/AddressValidatorGrpc.cs'
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:56.174, 40770644337571, datacollector.dll, [coverlet]Excluded source file: '/app/gen/Namely.Address.Grpc/ServiceGrpc.cs'
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:56.175, 40770644967637, datacollector.dll, [coverlet]Excluded source file: '/app/gen/Namely.Deductions.Grpc/DeductionsGrpc.cs'
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:56.176, 40770645934621, datacollector.dll, [coverlet]Excluded source file: '/app/gen/Namely.Paycycles.Grpc/ServiceGrpc.cs'
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:56.177, 40770646526554, datacollector.dll, [coverlet]Excluded source file: '/app/gen/Namely.PayCyclesConfiguration.Grpc/ServiceGrpc.cs'
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:56.177, 40770647420412, datacollector.dll, [coverlet]Instrumented module: '/app/test/PayrollSteps.Api.Test/bin/Release/netcoreapp3.1/PayrollSteps.Core.dll'
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:56.180, 40770649824113, datacollector.dll, [coverlet]Unable to instrument module: /app/test/PayrollSteps.Api.Test/bin/Release/netcoreapp3.1/Pipelines.Sockets.Unofficial.dll, embedded pdb without local source files, [C:\Code\Pipelines.Sockets.Unofficial\src\Pipelines.Sockets.Unofficial\ConnectionAbortedException.cs]
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:56.182, 40770651876921, datacollector.dll, [coverlet]Unable to instrument module: /app/test/PayrollSteps.Api.Test/bin/Release/netcoreapp3.1/Dapper.dll, embedded pdb without local source files, [C:\projects\dapper\Dapper\obj\Release\netstandard2.0\Dapper.Version.cs]
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:56.211, 40770681035814, datacollector.dll, [coverlet]Excluded module: '/app/test/PayrollSteps.Api.Test/bin/Release/netcoreapp3.1/xunit.execution.dotnet.dll'
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:56.212, 40770682471772, datacollector.dll, [coverlet]Unable to instrument module: /app/test/PayrollSteps.Api.Test/bin/Release/netcoreapp3.1/System.Interactive.Async.dll, embedded pdb without local source files, [D:\a\1\s\Ix.NET\Source\System.Interactive.Async\TaskExt.cs]
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:56.213, 40770683360430, datacollector.dll, [coverlet]Excluded module: '/app/test/PayrollSteps.Api.Test/bin/Release/netcoreapp3.1/xunit.runner.reporters.netcoreapp10.dll'
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:56.214, 40770684247247, datacollector.dll, [coverlet]Excluded module: '/app/test/PayrollSteps.Api.Test/bin/Release/netcoreapp3.1/xunit.core.dll'
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:56.218, 40770687554881, datacollector.dll, [coverlet]Unable to instrument module: /app/test/PayrollSteps.Api.Test/bin/Release/netcoreapp3.1/StackExchange.Redis.dll, embedded pdb without local source files, [C:\projects\stackexchange-redis\src\StackExchange.Redis\BufferReader.cs]
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:56.219, 40770688754131, datacollector.dll, [coverlet]Excluded module: '/app/test/PayrollSteps.Api.Test/bin/Release/netcoreapp3.1/xunit.runner.visualstudio.dotnetcore.testadapter.dll'
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:07:57.093, 40771563039587, datacollector.dll, [coverlet]Instrumented module: '/app/test/PayrollSteps.Api.Test/bin/Release/netcoreapp3.1/Namely.PayCyclesConfiguration.Shared.dll'
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:57.101, 40771571178779, datacollector.dll, DataCollectionRequestHandler.ProcessRequests : DataCollection started.
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:07:57.192, 40771661734182, datacollector.dll, DataCollectionRequestHandler.ProcessRequests : Datacollector received message: (DataCollection.TestHostLaunched) -> {
  "ProcessId": 80
}
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:17:28.144, 41342614504818, datacollector.dll, DataCollectionRequestHandler.ProcessRequests : Datacollector received message: (DataCollection.AfterTestRunEnd) -> false
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:17:28.153, 41342622719843, datacollector.dll, [coverlet]CoverletCoverageDataCollector: SessionEnd received
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:17:28.175, 41342644687785, datacollector.dll, AssemblyResolver.OnResolve: coverlet.collector.resources: Resolving assembly.
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:17:28.176, 41342645961243, datacollector.dll, AssemblyResolver.OnResolve: coverlet.collector.resources: Failed to load assembly.
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:17:28.177, 41342647125393, datacollector.dll, AssemblyResolver.OnResolve: coverlet.collector.resources: Resolving assembly.
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:17:28.178, 41342647928576, datacollector.dll, AssemblyResolver.OnResolve: coverlet.collector.resources: Resolved from cache.
TpTrace Warning: 0 : 61, 1, 2020/02/20, 06:17:28.191, 41342661101693, datacollector.dll, Data collector 'datacollector://microsoft/CoverletCodeCoverage/1.0' logged the following warning: [coverlet]Coverlet.Collector.Utilities.CoverletDataCollectorException: CoverletCoverageDataCollector: Failed to get coverage result
 ---> System.IO.IOException: The process cannot access the file '/tmp/PayrollSteps.Core_5073676f-963e-4708-b743-93afbcfe1425' because it is being used by another process.
   at System.IO.FileStream.Init(FileMode mode, FileShare share, String originalPath)
   at System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, FileOptions options)
   at System.IO.FileStream..ctor(String path, FileMode mode)
   at Coverlet.Core.Helpers.FileSystem.NewFileStream(String path, FileMode mode) in D:\git\coverletToRelease\src\coverlet.core\Helpers\FileSystem.cs:line 43
   at Coverlet.Core.Coverage.CalculateCoverage() in D:\git\coverletToRelease\src\coverlet.core\Coverage.cs:line 352
   at Coverlet.Core.Coverage.GetCoverageResult() in D:\git\coverletToRelease\src\coverlet.core\Coverage.cs:line 137
   at Coverlet.Collector.DataCollection.CoverageWrapper.GetCoverageResult(Coverage coverage) in D:\git\coverletToRelease\src\coverlet.collector\DataCollection\CoverageWrapper.cs:line 44
   at Coverlet.Collector.DataCollection.CoverageManager.GetCoverageResult() in D:\git\coverletToRelease\src\coverlet.collector\DataCollection\CoverageManager.cs:line 91
   --- End of inner exception stack trace ---
   at Coverlet.Collector.DataCollection.CoverageManager.GetCoverageResult() in D:\git\coverletToRelease\src\coverlet.collector\DataCollection\CoverageManager.cs:line 96
   at Coverlet.Collector.DataCollection.CoverletCoverageCollector.OnSessionEnd(Object sender, SessionEndEventArgs e) in D:\git\coverletToRelease\src\coverlet.collector\DataCollection\CoverletCoverageCollector.cs:line 148
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:17:28.195, 41342664821210, datacollector.dll, [coverlet]CoverletCoverageDataCollector: Disposing
TpTrace Error: 0 : 61, 1, 2020/02/20, 06:17:28.199, 41342669248902, datacollector.dll, DataCollectionAttachmentManager.GetAttachments: Fail to get attachments: System.Collections.Generic.KeyNotFoundException: The given key 'Microsoft.VisualStudio.TestPlatform.ObjectModel.DataCollection.DataCollectionContext' was not present in the dictionary.
   at System.Collections.Generic.Dictionary`2.get_Item(TKey key)
   at Microsoft.VisualStudio.TestPlatform.Common.DataCollector.DataCollectionAttachmentManager.GetAttachments(DataCollectionContext dataCollectionContext) 
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:17:28.200, 41342670445552, datacollector.dll, DataCollectionManager.CleanupPlugins: CleanupPlugins called
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:17:28.201, 41342671418493, datacollector.dll, DataCollectionManager.CleanupPlugins: Cleaning up 1 plugins
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:17:28.203, 41342673476068, datacollector.dll, dataCollectorInfo.DisposeDataCollector: calling Dispose() on Coverlet.Collector.DataCollection.CoverletCoverageCollector
TpTrace Verbose: 0 : 61, 1, 2020/02/20, 06:17:28.204, 41342674313052, datacollector.dll, [coverlet]CoverletCoverageDataCollector: Disposing
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:17:28.206, 41342675651077, datacollector.dll, DataCollectionManager.CleanupPlugins: CleanupPlugins finished
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:17:28.215, 41342684807085, datacollector.dll, DataCollectionRequestHandler.ProcessRequests : Session End message received from server. Closing the connection.
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:17:28.238, 41342708288552, datacollector.dll, Closing the connection !
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:17:28.240, 41342710045285, datacollector.dll, DataCollectionRequestHandler.ProcessRequests : DataCollection completed
TpTrace Information: 0 : 61, 1, 2020/02/20, 06:17:28.241, 41342711259810, datacollector.dll, Program.Main: exiting datacollector process.
TpTrace Information: 0 : 61, 20, 2020/02/20, 06:17:28.417, 41342886959036, datacollector.dll, DataCollector: ParentProcess '48' Exited.

[MarcoRossignoli]

Can you attach also "host" log(where inproc collector is injected)?
And also enable tracker? https://github.com/tonerdo/coverlet/blob/master/Documentation/Troubleshooting.md#enable-injected-tracker-log
To undestand if for some reason hit file is read when someone wants to persist-hit on the same.