Haxe 4.0.0-rc.2 is released

Dear Community,

On behalf of the Haxe Foundation, we are proud to announce the official release of the Haxe 4.0.0-rc.2! It is available along with the changelog at

We now support ES6 generation by using the -D es=6 flag! Please test this with your Haxe/JavaScript codebases and let us know about any problems you come across on ES6 class generation for Haxe/JS is here! (testers needed).

Other than that, we fixed a lot of bugs and improved the quality of our error messages a little.

See the changelog for further details. Please report any issues here:

Thank you very much for your help!


Massive! :slight_smile: Really cool to have ES6! I’m so impressed by the progress I’ve seen with Haxe just within the space of a few months :smiley:. Time to kick this baby into overdrive!

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WOW ! Thread support from Haxe level and not just at target language level got added ?

In …\HaxeToolkit_4_0_rc2/haxe/std/sys/thread/Thread.hx
package sys.thread;

It seems for Neko, Java, and C++ is that right ?

So we can use Threads from Haxe for those target languages ?

[std] Move target.vm.Thread (and friends) to sys.thread.Thread #7999

Thread support on these targets has been around for a long time. The only thing we changed here is to have the API available in the sys.thread package instead of spread out over the individual target namespaces.


If you would like to try haxe 4.0.0-rc.2 on a Raspberry Pi running Stretch…
I’m making a script in gist that compiles from source.
A small note, I’m compiling neko 2.2.0 without apache or mysql or gtk support

Feel free to test and give feedback, I tested it on a clean Raspbian Stretch
I had one hickup (missing dependency) ,but I think I’ve have worked that out now



Another way could be to base a script off haxe-docker’s Dockerfile for this target.

@kLabz, hey that’s very useful info thnx!
I kind of did it the hard way, by trial and error :wink:

i have notice that the code generated with es6 classes have less lines that with prototypes

I’m new to Haxe/OpenFl.
There will be breaking changes and should I wait for 4.0 GM or there is no upgrade issues ?