Merge pull request #67 from dtolnay/unwind

Clarify panic="unwind" requirement

README.md

@@ -70,7 +70,10 @@ provides the name of the offending function.
   detection. This includes `cargo build` of library crates and `cargo check` of
   binary and library crates.
 
-- The attribute is useless in code built with `panic = "abort"`.
+- The attribute is useless in code built with `panic = "abort"`. Code must be
+  built with `panic = "unwind"` (the default) in order for any panics to be
+  detected. After confirming absence of panics, you can of course still ship
+  your software as a `panic = "abort"` build.
 
 If you find that code requires optimization to pass `#[no_panic]`, either make
 no-panic an optional dependency that you only enable in release builds, or add a

src/lib.rs

@@ -79,7 +79,10 @@
 //!   detection. This includes `cargo build` of library crates and `cargo check`
 //!   of binary and library crates.
 //!
-//! - The attribute is useless in code built with `panic = "abort"`.
+//! - The attribute is useless in code built with `panic = "abort"`. Code must
+//!   be built with `panic = "unwind"` (the default) in order for any panics to
+//!   be detected. After confirming absence of panics, you can of course still
+//!   ship your software as a `panic = "abort"` build.
 //!
 //! If you find that code requires optimization to pass `#[no_panic]`, either
 //! make no-panic an optional dependency that you only enable in release builds,