jump through enough hoops for the poll lifetime to work out

you program rust for a few years and you think you're done tearing your
hair out over lifetimes, well, you'll find yourself wrong

crates/wasi-common/src/lib.rs

@@ -66,7 +66,7 @@ pub use cap_rand::RngCore;
 pub use clocks::{SystemTimeSpec, WasiClocks, WasiMonotonicClock, WasiSystemClock};
 pub use ctx::{WasiCtx, WasiCtxBuilder};
 pub use dir::WasiDir;
-pub use error::{Error, ErrorExt, ErrorKind};
+pub use error::{Context, Error, ErrorExt, ErrorKind};
 pub use file::WasiFile;
 pub use sched::{Poll, WasiSched};
 pub use string_array::StringArrayError;