fn echo() {
	println("echo")
	$if is_coroutine ? {
		println("coroutine")
	}
}

fn main() {
	go echo()
}

coroutines .so not found, downloading...
done!
================== C compilation error (from tcc): ==============
cc: /tmp/v_1000/coroutine_learn.01JJHGK3ZCB9N2GGW5VQ659HW9.tmp.c:5633: warning: implicit declaration of function 'delete_photon_work_pool'
cc: /mnt/star/program/vlang/v0.4.9/thirdparty/tcc/lib/libgc.a: error: 'GC_noop1_ptr' defined twice
cc: tcc: error: undefined symbol 'photon_thread_create_and_migrate_to_work_pool'
cc: tcc: error: undefined symbol 'delete_photon_work_pool'
... (the original output was 5 lines long, and was truncated to 4 lines)
=================================================================
(You can pass `-cg`, or `-show-c-output` as well, to print all the C error messages).
builder error: 
==================
C error found. It should never happen, when compiling pure V code.
This is a V compiler bug, please report it using `v bug file.v`,
or goto https://github.com/vlang/v/issues/new/choose .
You can also use #help on Discord: https://discord.gg/vlang .