[−]Constant syntax::source_map::SPAN_DEBUG
pub const SPAN_DEBUG: LocalKey<Cell<fn(Span, &mut Formatter) -> Result<(), Error>>>
🔬 This is a nightly-only experimental API. (rustc_private
)
this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml
instead?