I think that option 2 is the most reasonable at the moment (we can quickly achieve the goal) or maybe 3? And later when we deal with the most urgent issues we can think about 4…
But above all, I would like to know what will be the best in your opinion @ajsantander ?
We could perhaps have Legacy/Historic levels. I think Fallout is a great example of this. It’s nice to see how the tech has improved to prevent errors.
I like option 1 (testnets aren’t forever) or option 2 for pragmatism.
Also need to consider that this upgrade will need to be done periodically. So it won’t be the last time to do this.
I’ve seen the issues you created, thanks 
Are you planning to own any of them? Or maybe something from the board?
I’ll put them on the board, I just created the issues real quick late at night lol.
Do I have to be added to as a collaborator to be able to make contributions? I was unable to add issues to the project board.
Anyone can contribute, actually I’ve just added two of your issues to the board and assigned them to you 
I’d say that we go with option 1 for now and actually make this a super easy task… as @abcoathup pointed out, not upgrade some levels like Fallout in which using older solidity code is actually a feature. That said, it’s ok for Ethernaut to have levels in older solidity code, but It’d be nice to upgrade the levels that can be upgraded every now and then, so that the game doesn’t look outdated.
Sounds good to me - often the easiest solutions are the best
Ethernaut is often used for learning, so code should represent good Solidity practices. What do you think about applying SafeMath for arithmetic operations (of course, where it does not spoil the game)?
SafeMath was not used before to keep things as simple as possible, but I agree with you that it’s more important to reinforce best practices.
If you can produce a PR with these changes I should be able to merge it and re-reploy in the upcoming days!
As a contribution guide standard I personally think we should start a slack or discord channel for those in interested in Dev work. It’ll also help keep everyone up to date without having to check the forum all the time and possibly miss vital info. It’s just my opinion but it could have potential. Tron has the same thing where they have a discord for devs and a telegram for their main place of communicating general stuff.
Do we still want to integrate Ethernaut with Zos?
We had a slack (and have a telegram channel), but we moved away since:
Why do you think checking the forum is something bad? 
I actually think it's way easier to miss something in a chat than in a forum 
Is level 5 (Token) the only that shouldn’t use SafeMath?
What do you think, is it better to use some old version of openzeppelin-solidity library and do it now or wait for Solidity 0.5 update?
I never did think of maintenance, I’m so used to stuff being on slack and chats like that. Good points made, I’ll get into the habit of checking the forum more often.
I’m not sure if that level is the only one, but as I recall, only one was based on an overflow vulenrability, so most likely yes.
Regarding the openzeppelin-solidity dependency, why do we have those two options?
We definitely do, but not for the time being. It’s a big refactor. I think we should go with the simpler solutions first and deal with more complex topics like this as our todo list shrinks…
I used openzeppelin-solidity v.2.1.0, with newer versions there was a problem with contracts compilation. I have just created PR
Hi, today I am going on a short vacation and I am coming back on 9 May. I will be offline at this time. But on my return I will continue working on Solidity 0.5 
Hi! Have some well deserved rest – we already miss you
If you’re thinking of traveling, feel free to come by Zeppelin’s HQ in Buenos Aires 