Is the try_runtime_upgrade error type needed?

[Chralt98]

When using unwrap it stops executing the code. Why is the return parameter &'static str needed here then?

Wouldn't it have the same effect to replace it with the following?

pub fn try_runtime_upgrade() -> Result<frame_support::weights::Weight, ()>

Related to this.

[bkchr]

I don't get the question?

[Chralt98]

Sorry about that. Just for clarification: I thought, that unwrap would lead to stop the running code. Therefore I thought, that returning a &' static str would not have an effect to the caller of the try_runtime_upgrade() function.

The second point when using this function:
I saw the example of KILT spiritnet here and wondered, if this log::info would ever be called. I reproduced the scenario here and think still, that the log::info is unreachable there.

[shawntabrizi]

Copying the same thing I posted in your linked issue:

You shouldn't be using unwrap, you should be handling the result with something like ? or similar.

Of course if you unwrap and cause a panic, you will not trigger proper Rust error handling.

So, just like regular Rust, if you want to take advantage of Rust error handling, you should not be using unwrap or other panic inducing code.

On the other hand, if you correctly handle the Rust errors, you will see the &'static str printed for you, so this is why it is part of the signature of the function return.