exit status: 1 with stderr:
<stdin>:3:9: warning: initialization of immutable value 'a' was never used; consider replacing with assignment to '_' or removing it let a = 0 ~~~~^ _ <stdin>:2:19: error: cannot capture 'a' before it is declared defer { print(a) } // ←まだaが宣言されてないよ…？ <stdin>:3:9: note: 'a' declared here let a = 0 ^