On Monday (June 20), Charles Hoskinson, Co-Founder and CEO of IO Global (aka “IOG”, formerly known as “IOHK”), the company responsible for Cardano’s research and development, explained why the Vasil hard fork will not be going live on the mainnet on June 29 as originally planned.

Yesterday, Nigel Hemsley, Head of Delivery & Projects at IOG, published a blog post titled “Vasil upgrade – the state of play”.

Hemsley wrote:

The IOG engineering team is extremely close to finalizing the core work, with just seven bugs still outstanding to complete the hard fork work, with none currently ranked as ‘severe’. After some consideration, we have agreed NOT to send the hard fork update proposal to the testnet today to allow more time for testing…

To date, we’ve managed to get through the majority (approx 95%) of our Plutus V2 test scripts. However, we still have a few outstanding items that we need to run to confirm everything is working as expected. We have determined we’ll need a few more days for this. This puts us behind schedule on our previously communicated target date of June 29 for a mainnet hard fork…

Today, IOG and the Cardano Foundation have agreed a new target date to hard fork the testnet at the end of June. Once completed, we will then allow four weeks for exchanges and SPOs to carry out any required integration and testing work. This is only reasonable and should not be rushed. The working assumption should therefore now be a Cardano mainnet hard fork occurring during the last week of July.

A short time afterwards, the IOG CEO made a 15-minute video to share his thoughts on the Vasil upgrade delay.

Hoskinson said:

We’re pretty close to the target. We’re code complete, and what code complete effectively means is you probably could flip the switch and get away with it, and certain projects would do that, but what happened after the collapse of Terra (LUNA) is that I gave a directive to a lot of engineers to say we should probably measure three times and cut once given the nature of things.

And so, additional tests were added in the Plutus suite and additional work was done for QA above and beyond what we normally do for hard forks. So, that was one dimension of the puzzle that made it more complicated.

The other dimension of the puzzle was that after Consensus we did have an enormous amount of contact with dApp developers and other people, and there was a desire to be a bit more inclusive in the QA process and the testing process. A lot of them said ‘hey, we need several weeks on testnet to be able to play around with these things’. And at the end of the day, this is not a hard fork for the average Cardano user. The Vasil hard fork has always been a hard fork specifically for dApp developers.

It speeds up the transaction rate with pipelining. And then all the CIPs are basically there to make Plutus smart contracts easier to write. If you’re a developer, whether you’re doing it on the mainnet or the testnet, you should have the same development environment in that respect.

So what’s more meaningful to the community, frankly, is making sure that the testnet runs Vasil so that people who are building dAps on Cardano can deploy those dApps… We don’t anticipate that this July date is going to in any way impact the actual rollout of all the dApps have been waiting for Vasil because now they have a testing environment to do that...

July is not too far off, you know, and all things considered, it’s kind of in an acceptable zone in my view. It’s a little frustrating because I really wanted to make sure that we got something in June, but getting it on the testnet I think is good enough for the developers because they’re the primary constituent here, and that’s not going to slow down ecosystem growth.

On Tuesday (June 14), Dan Gambardello, Founder of Crypto Capital Venture, had this to say about the delay of the Vasil upgrade (on the mainnet) to the last week of June: