Copy-paste fix pattern
library CB-Render
fn main() {
init_window(640, 360, "Window")
clear(0x071018)
swap_buffers_fast()
}Why it happens
The checker found a function call that is not built in and is not defined in this source or a loaded library.
How to fix it
Check spelling, add the required library, or define the function before calling it.
If the IDE reports a line number, fix that line first, then scan the previous line for an unclosed string, bracket, or block.