I checked that discussion. That isn't what i'm talking about. We don't need to pin our project to a specific .NET Core SDK as it works on different versions just fine. I was trying to point out that the update notes seem to be indicating that .NET Core SDK 2.2.203 was installed, but that is only supposed to be used in Visual Studio 2019. The equivalent SDK for Visual Studio 2017 is 2.2.106 (see https://dotnet.microsoft.com/download/thank-you/dotnet-sdk-2.2.106-...).
Since our project builds fine on our machines using the newest version of the SDK meant for Visual Studio 2017 (2.2.106) it leads me to believe that 2.2.203 was incorrectly installed as part of your latest update, leading to our project failing to build.
What puzzles me is that our own production and test .NET Core projects which use SDK 2.2.203 are being built fine. Also we have no other complains. So this maybe some special case we need to investigate. So repro would be great.
@Renato I did not look deep. It is just my first instinct to update the the failing components to the last version when other components has been updated recently. If you want to investigate, you can set Cake.Tool version back to the old one and increase it's verbosity to the highest level.
In my efforts to make a simple reproducible case I realized that I hadn't been clear. What started failing is some tests that run as part of our build.
Before the weekend I had updated my local SDK from version 2.2.103 to 2.2.106 when our Appveyor build (tests) started to break. I re-ran the build and the tests and everything passed. I then looked at what had changed and saw what I believed (and still believe) to be the wrong version (2.2.203) of the SDK for vs 2017.
Yesterday while trying to make a simple repro, using version 2.2.106 I started to have the same errors locally when running the tests after a build. This would seem to indicate that some behaviour changed between version 2.2.103 which I had previously and the new 2.2.106. Since the issue is now reproducible locally, this doesn't seem to be an issue with the Visual Studio image that Appveyor has.
Thanks for the update. I filed https://github.com/appveyor/ci/issues/2925 to investigate before next image update. However my feeling that this is mostly related to VS and unrelated to msbuild which is version 15 for both VS2017 and VS2019.
I think we still have to install the latest SDK + ensure the latest for specific VS version (in this case 2.2.106) is installed too.