Dotnet core ignores ASPNETCORE_ENVIRONMENT variable

I suspect that the issue you're encountering is that the ASPNETCORE_ENVIRONMENT variable is defined in the C:\devel\apps\webapi\Properties\launchSettings.json file.

The way dotnet run works is it loads this file and finds the first profile which commandName is project, and uses it to run the application. There's a high chance, if you haven't made any changes to that file, that the environmentVariables section of that profile contains the ASPNETCORE_ENVIRONMENT variable set to Development.

You have 2 options if you want to run the app in Production mode:

• change the existing profile and set the variable to Production, meaning every time you execute dotnet run, it's going to run the app in production mode; or
• add a new profile where the ASPNETCORE_ENVIRONMENT variable is set to Production. You can then use it if you execute dotnet run --launch-profile <name-of-your-new-profile>

The problem is how you have set the environment variable. On the command line you don't need the quotes, so you should instead have this:

C:\> set ASPNETCORE_ENVIRONMENT=Production

C:\> echo %ASPNETCORE_ENVIRONMENT%
Production