bug: compiler panic when returning empty constant

[tserg]

Version Information

• vyper Version (output of vyper --version): a0d9b1ff0206c7916bce7987164dbdb69f460c47
• OS: linux
• Python Version (output of python --version): 3.12.3

What's your issue about?

The following contracts that used to compile in v0.3.9 now fail compilation. I have traced it to 56c4c9dbc09d6310bf132cfde3fdbe1431189a9b.

BOO: constant(uint256[3]) = empty(uint256[3])

@external
def foo() -> uint256[3]:
    return BOO

vyper.exceptions.CompilerPanic: unreachable!

  contract "tmp/empty_list.vy:7", function "foo", line 7:4 
       6 #def foo() -> DynArray[uint256, 3]:
  ---> 7     return BOO
  -----------^
       8     #return empty(uint256[3])

This is an unhandled internal compiler error. Please create an issue on Github to notify the developers!

BOO: constant(DynArray[uint256, 3]) = empty(DynArray[uint256, 3])

@external
def foo() -> DynArray[uint256, 3]:
    return BOO

vyper.exceptions.CompilerPanic: cannot dereference non-pointer type

  contract "tmp/empty_list.vy:7", function "foo", line 7:4 
       6 def foo() -> DynArray[uint256, 3]:
  ---> 7     return BOO
  -----------^
       8     #return empty(uint256[3])

This is an unhandled internal compiler error. Please create an issue on Github to notify the developers!

How can it be fixed?

Fill this in if you know how to fix it.

[tserg]

Structs are affected too.