I just installed haxe today and the lime extension for VSCode but when I try to open a project it reports “Haxe version check failed: “/bin/sh: line 1: haxe: command not found”“. I am on steamos witch is a branch of Arch Linux. On Haxe version 4.3.6 (I think that’s the latest).
Welcome! I’m not familiar with Arch Linux (I use Fedora) or VS Code, but it seems like it cannot see the installed haxe binary. When you open a terminal and type haxe --version, what is the output? If even your shell cannot see it, then it means that the Haxe binary isn’t in any of the directories that are part of your PATH environment variable that are traversed when executing commands and searching for their corresponding binaries.
You can see the list of directories that your shell traverses looking for binaries by running echo $PATH.
How did you install Haxe? Was it through the VS Code, or did you do so through the specific instructions for Arch Linux at Haxe - The Cross-platform Toolkit? Also, that page states that Haxe 4.3.7 is the latest version, but it’s unclear if that would be related to the issue here.
Welcome to the community @MrBean 
Can you share the output of:
pacman -Q | grep haxe
I’m successfully using Haxe + VS Code under Arch based Linux (EndeavourOS).
Also, what version of VS Code did you install? Was it code from the official Arch repo? I’d recommend that.