= note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `std::panic` (in Nightly builds, run with -Z macro-backtrace for more info)
= note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `std::panic` (in Nightly builds, run with -Z macro-backtrace for more info)
= note: this error originates in the macro `$crate::panic::unreachable_2015` which comes from the expansion of the macro `std::unreachable` (in Nightly builds, run with -Z macro-backtrace for more info)
= note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `std::panic` (in Nightly builds, run with -Z macro-backtrace for more info)
= note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `std::panic` (in Nightly builds, run with -Z macro-backtrace for more info)
= note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `core::panic` (in Nightly builds, run with -Z macro-backtrace for more info)
= note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `core::panic` (in Nightly builds, run with -Z macro-backtrace for more info)
= note: this error originates in the macro `$crate::panic::unreachable_2015` which comes from the expansion of the macro `core::unreachable` (in Nightly builds, run with -Z macro-backtrace for more info)
= note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `core::panic` (in Nightly builds, run with -Z macro-backtrace for more info)
= note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `core::panic` (in Nightly builds, run with -Z macro-backtrace for more info)