Alice adds a second migration which adds and initializes another column to the +products+ table and also adds a validation to the Product model for the new column.
@@ -575,12 +575,12 @@ Bob comes back from vacation and:
The migration crashes because when the model attempts to save, it tries to validate the second added column, which is not in the database when the _first_ migration runs.
<pre>
<plain>
rake aborted!
An error has occurred, this and all later migrations canceled:
undefined method `fuzz' for #<Product:0x000001049b14a0>
</pre>
</plain>
A fix for this is to create a local model within the migration. This keeps rails from running the validations, so that the migrations run to completion.
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@@ -588,7 +588,7 @@ When using a faux model, it's a good idea to call +Product.reset_column_informat
If Alice had done this instead, there would have been no problem: