Vyper raises one or more of the following exceptions when an issue is encountered while compiling a contract.
Whenever possible, exceptions include a source highlight displaying the location of the error within the code:
vyper.exceptions.VariableDeclarationException: line 79:17 Persistent variable undeclared: highstBid
78 # If bid is less than highest bid, bid fails
---> 79 if (value <= self.highstBid):
-------------------------^
80 return False.. py:exception:: ArgumentException
Raises when calling a function with invalid arguments, for example an incorrect number of positional arguments or an invalid keyword argument.
.. py:exception:: CallViolation
Raises on an illegal function call, such as attempting to call between two external functions.
.. py:exception:: ArrayIndexException
Raises when an array index is out of bounds.
.. py:exception:: EventDeclarationException
Raises when an event declaration is invalid.
.. py:exception:: EvmVersionException
Raises when a contract contains an action that cannot be performed with the active EVM ruleset.
.. py:exception:: FunctionDeclarationException
Raises when a function declaration is invalid, for example because of incorrect or mismatched return values.
.. py:exception:: ImmutableViolation
Raises when attempting to perform a change a variable, constant or definition that cannot be changed. For example, trying to update a constant, or trying to assign to a function definition.
.. py:exception:: InterfaceViolation
Raises when an interface is not fully implemented.
.. py:exception:: InvalidAttribute
Raises on a reference to an attribute that does not exist.
.. py:exception:: InvalidLiteral
Raises when no valid type can be found for a literal value.
.. code-block:: python
@external
def foo():
bar: decimal = 3.123456789123456789
This example raises ``InvalidLiteral`` because the given literal value has too many decimal places and so cannot be assigned any valid Vyper type.
.. py:exception:: InvalidOperation
Raises when using an invalid operator for a given type.
.. code-block:: python
@external
def foo():
a: String[10] = "hello" * 2
This example raises ``InvalidOperation`` because multiplication is not possible on string types.
.. py:exception:: InvalidReference
Raises on an invalid reference to an existing definition.
.. code-block:: python
baz: int128
@external
def foo():
bar: int128 = baz
This example raises ``InvalidReference`` because ``baz`` is a storage variable. The reference to it should be written as ``self.baz``.
.. py:exception:: InvalidType
Raises when using an invalid literal value for the given type.
.. code-block:: python
@external
def foo():
bar: int128 = 3.5
This example raises ``InvalidType`` because ``3.5`` is a valid literal value, but cannot be cast as ``int128``.
.. py:exception:: IteratorException Raises when an iterator is constructed or used incorrectly.
.. py:exception:: JSONError
Raises when the compiler JSON input is malformed.
.. py:exception:: NamespaceCollision
Raises when attempting to assign a variable to a name that is already in use.
.. py:exception:: NatSpecSyntaxException
Raises when a contract contains an invalid :ref:`NatSpec<natspec>` docstring.
.. code-block:: python
vyper.exceptions.SyntaxException: line 14:5 No description given for tag '@param'
13 @dev the feet are sticky like rice
---> 14 @param
-------------^
15 @return always True
.. py:exception:: NonPayableViolation
Raises when attempting to access ``msg.value`` from within a function that has not been marked as ``@payable``.
.. code-block:: python
@public
def _foo():
bar: uint256 = msg.value
.. py:exception:: OverflowException
Raises when a numeric value is out of bounds for the given type.
.. py:exception:: StateAccessViolation
Raises when attempting to perform a modifying action within view-only or stateless context. For example, writing to storage in a ``@view`` function, reading from storage in a ``@pure`` function.
.. py:exception:: StructureException
Raises on syntax that is parsable, but invalid in some way.
.. code-block:: python
vyper.exceptions.StructureException: line 181:0 Invalid top-level statement
180
---> 181 '''
---------^
182
.. py:exception:: SyntaxException
Raises on invalid syntax that cannot be parsed.
.. code-block:: python
vyper.exceptions.SyntaxException: line 4:20 invalid syntax
3 struct Bid:
---> 4 blindedBid bytes32
---------------------------^
5 deposit: uint256
.. py:exception:: TypeMismatch
Raises when attempting to perform an action between two or more objects with known, dislike types.
.. code-block:: python
@external
def foo(:
bar: int128 = 3
foo: decimal = 4.2
if foo + bar > 4:
pass
``foo`` has a type of ``int128`` and ``bar`` has a type of ``decimal``, so attempting to add them together raises a ``TypeMismatch``.
.. py:exception:: UndeclaredDefinition
Raises when attempting to access an object that has not been declared.
.. py:exception:: VariableDeclarationException
Raises on an invalid variable declaration.
.. code-block:: bash
vyper.exceptions.VariableDeclarationException: line 79:17 Persistent variable undeclared: highstBid
78 # If bid is less than highest bid, bid fails
---> 79 if (value <= self.highstBid):
-------------------------^
80 return False
.. py:exception:: VersionException
Raises when a contract version string is malformed or incompatible with the current compiler version.
.. py:exception:: ZeroDivisionException
Raises when a divide by zero or modulo zero situation arises.
.. py:exception:: CompilerPanic
::
$ vyper v.vy
Error compiling: v.vy
vyper.exceptions.CompilerPanic: Number of times repeated
must be a constant nonzero positive integer: 0 Please create an issue.
A compiler panic error indicates that there is a problem internally to the compiler and an issue should be reported right
away on the Vyper Github page. Open an issue if you are experiencing this error. Please `Open an Issue <https://github.com/vyperlang/vyper/issues>`_