Maybe you can add this to your Startup.Configure ?

            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }

I set the LogLevel to Trace for everything and in the Output window I see it trying to apply all of the update scripts.
However, it's trying to do this in 12.8.0.sql

ALTER TABLE [dbo].[tblMappedIdentity]
    ADD [Metadata] NVARCHAR (MAX) NULL,
        [Saved]    DATETIME       NULL;

but my cms11 database already looks like this...



the error:

System.Data.DataException: Failed to update database during execution of statement 'ALTER TABLE [dbo].[tblMappedIdentity]
    ADD [Metadata] NVARCHAR (MAX) NULL,
        [Saved]    DATETIME       NULL;
'
 ---> Microsoft.Data.SqlClient.SqlException (0x80131904): Column names in each table must be unique. Column name 'Metadata' in table 'dbo.tblMappedIdentity' is specified more than once.
   

I see, it is possible to just drop the two columns and proceed - especially as this is for local development it should not have any consequences.

I will look into this to see if we can do anything about it 

I tried your suggestion and removed the two columns. The db upgrade script now gets to 12.8.0.sql and errors trying to create a stored proc.

Microsoft.Data.SqlClient.SqlException (0x80131904): There is already an object named 'netMappedIdentitySetMetadata' in the database.

I deleted the stored proc 'netMappedIdentitySetMetadata' and now the db updates finish without an error.

Public Bug posted: https://world.optimizely.com/support/bug-list/bug/CMS-31381