Compiling stm32l0xx-hal v0.0.1 (/Users/arko/GitHub/stm32l0xx-hal)
error[E0658]: The attribute `interrupt` is currently unknown to the compiler and may have meaning added to it in the future (see issue #29642)
  --> examples/timer.rs:41:3
   |
41 | #[interrupt]
   |   ^^^^^^^^^

error: aborting due to previous error

For more information about this error, try `rustc --explain E0658`.
error: Could not compile `stm32l0xx-hal`.

To learn more, run the command again with --verbose.