vlib/v/checker/tests/run/unused_variable_warning.vv:3:2: warning: unused variable: `a`
    1 | // NB: this test should compile and run, but it also should produce a compiler warning.
    2 | fn main() {
    3 |     a := 1
      |     ^
    4 |     b := 2
    5 |     println('hello')
vlib/v/checker/tests/run/unused_variable_warning.vv:4:2: warning: unused variable: `b`
    2 | fn main() {
    3 |     a := 1
    4 |     b := 2
      |     ^
    5 |     println('hello')
    6 | }
hello