in symfony 4 forms, is it possible to manipulate the ‘attr’ value of a form element in a form event listener without deleting and re-creating the input?

I changed php version and composer version.But run command “bin/magento setup:upgrade”, display error like this. SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry […]

I’ve been trying to add phtml to my custom theme but it doesn’t show for example <block class=”MagentoCatalogBlockProductView” name=”product_view_custom_block” before=”-” template=”Magento_Catalog::product/view/custom_block.phtml”/> path […]