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kotlinlang

For JVM development targeting server-side, how alpha is the k2 version inside 1.7 ?

Some simpler projects build and pass tests without issue

I mean what are recommendations for use, is it really just a feature preview or could it be used in real projects

I was thinking to switch to it for development/test cycle and then have CI builds run the old compiler

K2 compiler produces pre-release binaries, so it's not recommended to use it in production (there are some incompatible binary still possible)
But it's ok to use it, for example, for local development

yes ok, so considered ready for development. Great!

&gt; I was thinking to switch to it for development/test cycle and then have CI builds run the old compiler
Yeah, it's what I meant
We in compiler team use this scheme with Kotlin project itself for ~9 month, and everything works more or less great

I had zero issues with smaller projects but encountered classcast exceptions which seem to come from different java module results with k2? I will post detailed bug report

It's interesting. Report will be helpful, thanks

Anyway, this is exciting and great work so far! :tulip: 

I will try make kotlinOptions.useK2 = !isCiServer

In Kotlin project we use special gradle properties provider, which looks to `local.properties` file before `gradle.properties`, which allows each developer to customize his local environment

this is the bug I found in 1.7 k2. `as?` operator seems broken

<https://youtrack.jetbrains.com/issue/KT-52580/Safe-cast-operator-lets-ClassCastException-escape-when-compiled-with-k2-compiler>