dotnet test seems to ignore runsettings MaxCpuCount

Description

dotnet test when run against a solution that contains multiple test projects, appears to spin up a parallel test runner for each test project.

Attempting to limit to one test runner at a time via the MaxCpuCount value in a .runsettings file doesn’t work.

Steps to reproduce

1. Create a solution with two or more test projects that use NUnit
2. Create a .runsettings file that sets MaxCpuCount=1
3. run dotnet test --settings pathtofile.runsettings

Expected behavior

Tests assemblies are run sequentially

Actual behavior

Test assemblies are run in parallel (seen in my case where the tests are database tests and they end up fighting for access to the database)

Diagnostic logs

Environment

Windows 10 1809, vstest.console 15.0.28307.421 .NET Core SDK 2.2.200/2.2.202

[smchan514]

For anyone still looking for a solution, there is the command line option -m:1 which specifies the maximum number of concurrent processes to use when building.

dotnet test -m:1 MyUnitTests.sln

Ref:

1. https://github.com/dotnet/sdk/issues/10178
2. MSBuild command-line reference – Switches

[Mpdreamz]

Even the fact that console loggers will be intermixed makes me want to run sequentially on CI to get sane output. MaxCpuCount is not a fix.

Please reconsider reopening this.