If I run dotnet ef add testmigration
dotnet ef add testmigration
I get this warning: The EF Core tools version \'2.1.0-rtm-30799\' is older than that of the runtime \'2.1.1-r
The EF Core tools version \'2.1.0-rtm-30799\' is older than that of the runtime \'2.1.1-r
Ok.
Turns out that this is caused by having the second latest sdk installed (2.1.301), but somewhere in the path a global.json pinned to version 2.1.300.