The `syn` approach requires use of `::pin_init::...` instead of the
`$crate::...` construct available to declarative macros. To be able to
use the `pin_init` crate from itself (which includes doc tests), we have
to declare it as such.

Signed-off-by: Benno Lossin <lossin@kernel.org>
---
 rust/pin-init/src/lib.rs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/rust/pin-init/src/lib.rs b/rust/pin-init/src/lib.rs
index 8673008f45d2..0e707f00061f 100644
--- a/rust/pin-init/src/lib.rs
+++ b/rust/pin-init/src/lib.rs
@@ -290,6 +290,11 @@
     ptr::{self, NonNull},
 };
 
+// This is used by doc-tests -- the proc-macros expand to `::pin_init::...` and without this the
+// doc-tests wouldn't have an extern crate named `pin_init`.
+#[allow(unused_extern_crates)]
+extern crate self as pin_init;
+
 #[doc(hidden)]
 pub mod __internal;
 #[doc(hidden)]
-- 
2.51.2