Windows example build error

[matkuki]

Hi,

Specs:

• Windows 10
• Vale 0.2.0

running valec build mymod=myprogram.vale --output_dir build with file myprogram.vale:

exported func main() {
  println("Hello world!");
}

throws:

$ valec build mymod=myprogram.vale --output_dir build
Unable to find program java.exe.
(panic)

[Verdagon]

Part of the Vale compiler is written in Scala, so the user needs to have java installed to run it.

We could use a better error message here, I'll leave this issue open as a reminder to do that.