In go errors pkg can create a joinErr by errors.Join(), which can be Unwrap() into []error.
joinErr also format it's print into \n separated string, which is similar with gin.errorMsgs.String() but can cause confuse, when they are used together:

Error #01 gin error
Error #02 service error
store error
Error #03 other error

In this case service error & store error is combined with a joinErr.
I think it will be better if we can see:

Error #01 gin error
Error #02 service error
Error #03 store error
Error #04 other error

Even though we can unwrap joinErr before we use gin.Error(), it will be better if gin.Error() do the unwrap for us as a internal logic.