What am I doing wrong?

gistfile1.rs

/// Retrieves a value for the given key. A passed default value is
/// returned if the key is not present.
pub fn get_or_default<'a>(&'a self, k: &K, default: &V) -> &'a V {
    match self.find(k) {
        Some(v) => v,
        None => default
    }
}

gistfile2.txt

milos in rust > make
cfg: build triple x86_64-apple-darwin
cfg: host triples x86_64-apple-darwin
cfg: target triples x86_64-apple-darwin
cfg: host for x86_64-apple-darwin is x86_64
cfg: os for x86_64-apple-darwin is apple-darwin
cfg: using clang
cfg: enabling valgrind (CFG_ENABLE_VALGRIND)
cfg: no pdflatex found, omitting doc/rust.pdf
cfg: no llnextgen found, omitting grammar-verification
compile_and_link: x86_64-apple-darwin/stage0/lib/rustc/x86_64-apple-darwin/lib/libstd.dylib
/Users/milos/.build/rust/src/libstd/hashmap.rs:422:8: 425:9 error: cannot infer an appropriate lifetime due to conflicting requirements
/Users/milos/.build/rust/src/libstd/hashmap.rs:422         match self.find(k) {
/Users/milos/.build/rust/src/libstd/hashmap.rs:423             Some(v) => v,
/Users/milos/.build/rust/src/libstd/hashmap.rs:424             None => default
/Users/milos/.build/rust/src/libstd/hashmap.rs:425         }
/Users/milos/.build/rust/src/libstd/hashmap.rs:421:69: 426:5 note: first, the lifetime cannot outlive the anonymous lifetime #2 defined on the block at 421:69...
/Users/milos/.build/rust/src/libstd/hashmap.rs:421     pub fn get_or_default<'a>(&'a self, k: &K, default: &V) -> &'a V {
/Users/milos/.build/rust/src/libstd/hashmap.rs:422         match self.find(k) {
/Users/milos/.build/rust/src/libstd/hashmap.rs:423             Some(v) => v,
/Users/milos/.build/rust/src/libstd/hashmap.rs:424             None => default
/Users/milos/.build/rust/src/libstd/hashmap.rs:425         }
/Users/milos/.build/rust/src/libstd/hashmap.rs:426     }
/Users/milos/.build/rust/src/libstd/hashmap.rs:422:8: 425:9 note: ...due to the following expression
/Users/milos/.build/rust/src/libstd/hashmap.rs:422         match self.find(k) {
/Users/milos/.build/rust/src/libstd/hashmap.rs:423             Some(v) => v,
/Users/milos/.build/rust/src/libstd/hashmap.rs:424             None => default
/Users/milos/.build/rust/src/libstd/hashmap.rs:425         }
/Users/milos/.build/rust/src/libstd/hashmap.rs:421:69: 426:5 note: but, the lifetime must be valid for the lifetime &'a  as defined on the block at 421:69...
/Users/milos/.build/rust/src/libstd/hashmap.rs:421     pub fn get_or_default<'a>(&'a self, k: &K, default: &V) -> &'a V {
/Users/milos/.build/rust/src/libstd/hashmap.rs:422         match self.find(k) {
/Users/milos/.build/rust/src/libstd/hashmap.rs:423             Some(v) => v,
/Users/milos/.build/rust/src/libstd/hashmap.rs:424             None => default
/Users/milos/.build/rust/src/libstd/hashmap.rs:425         }
/Users/milos/.build/rust/src/libstd/hashmap.rs:426     }
/Users/milos/.build/rust/src/libstd/hashmap.rs:422:8: 425:9 note: ...due to the following expression
/Users/milos/.build/rust/src/libstd/hashmap.rs:422         match self.find(k) {
/Users/milos/.build/rust/src/libstd/hashmap.rs:423             Some(v) => v,
/Users/milos/.build/rust/src/libstd/hashmap.rs:424             None => default
/Users/milos/.build/rust/src/libstd/hashmap.rs:425         }
error: aborting due to previous error
make: *** [x86_64-apple-darwin/stage0/lib/rustc/x86_64-apple-darwin/lib/libstd.dylib] Error 101