Notice :Undefined index: display_price in uc_taxes_entity_view_alter() line 114

What do you mean by "auction post"? If you are using uc_auction or a similar module, then this issue probably needs to be fixed in that module.

I'm having the same problem trying to set up an auction product.

Notice: Undefined index: display_price in uc_taxes_entity_view_alter() (line 114 of xxxxx/modules/ubercart/uc_taxes/uc_taxes.module).
Notice: Undefined index: #value in uc_taxes_entity_view_alter() (line 114 of xxxxx/modules/ubercart/uc_taxes/uc_taxes.module).

I'm having the same problem.
I investigated the cause of the Notice.

This is occurred when "auction settings(on the each product edit) -> This is an auctioned product." is checked.

So I printed $build by using dsm like below.

function uc_taxes_entity_view_alter(&$build, $entity_type) {
dsm($build);

If "This is an auctioned product."(in short auction option) is checked ,
I couldn't find 'display_price' and could find uc_auction.
If the auction option is not checked ,
I could find 'display_price' and couldn't find uc_auction.

So I changed code to
when only the auction option is not checked ,
"if" phrase is executed.

It's like below.
before:if (uc_product_is_product($build['#node'])) {
after:if (uc_product_is_product($build['#node']) and empty($build['uc_auction'])) {
...

As doing like above,
the "Notice :Undefined index: display_price" is disappeared.

I know it's not right way.

but I don't know what is $build['display_price']['#value'],
where , how and when it is used.

I'm not familiar with the whole ubercart architecture. But I need to fix this error. So either I fix it in the main ubercart or in uc_auction. As uc_auction is a smaller module, thus changing few lines of codes in uc_auction is not as critical as changing few lines of codes in main ubercart modules. Furthermore, the suspect code in uc_auction is concentrated in few lines.

Here's the patch. Instead of unsetting the 3 array elements, use #access property to hide the 3 elements for auctionable products. With this, the original array elements required by ubercart are not disturbed.