[False-Positive]: Vyper constant-states

[trocher]

Describe the false alarm that Slither raises and how you know it's inaccurate:

Slither can report that a non-constant state variable that is being updated should be constant.

Additionally, there seems to be some non-determinism involved as it is not reported every time (running Slither multiple times without changing the file can yield a different amount of results each time) See in the log output two consecutive run results.

[EDIT] the issue seems to be fixed on the dev branch

Frequency

Very Frequently

Code example to reproduce the issue:

# @version 0.3.7

x: public(uint256)

@external
def foo():
    x:uint256 = 12
    x += 1
    self.x = x

Version:

0.10.1

Relevant log output:

~/shared/ slither contracts/lending/Foo.vy
INFO:Detectors:
Foo.foo().x (contracts/lending/Foo.vy#7) shadows:
	- Foo.x (contracts/lending/Foo.vy#3) (state variable)
Reference: https://github.com/crytic/slither/wiki/Detector-Documentation#local-variable-shadowing
INFO:Detectors:
Foo.x (contracts/lending/Foo.vy#3) should be constant
Reference: https://github.com/crytic/slither/wiki/Detector-Documentation#state-variables-that-could-be-declared-constant
INFO:Slither:contracts/lending/Foo.vy analyzed (1 contracts with 94 detectors), 2 result(s) found

~/shared/ slither contracts/lending/Foo.vy
INFO:Detectors:
Foo.foo().x (contracts/lending/Foo.vy#7) shadows:
	- Foo.x (contracts/lending/Foo.vy#3) (state variable)
Reference: https://github.com/crytic/slither/wiki/Detector-Documentation#local-variable-shadowing
INFO:Slither:contracts/lending/Foo.vy analyzed (1 contracts with 94 detectors), 1 result(s) found