Build failed

[gentoo90]

Build from the latest master (9f66dddf) fails with the latest nightly rust:

$ rustc -V
rustc 1.23.0-nightly (5f44c653c 2017-11-24)
$ cargo build
   Compiling semver-parser v0.7.0
   Compiling unicode-segmentation v1.2.0
   Compiling regex-syntax v0.4.1
   Compiling unicode-xid v0.0.4
   Compiling libc v0.2.33
   Compiling diff v0.1.11
   Compiling bitflags v1.0.1
   Compiling dtoa v0.4.2
   Compiling quote v0.3.15
   Compiling cfg-if v0.1.2
   Compiling rustfmt v0.9.0
   Compiling cc v1.0.3
   Compiling getopts v0.2.15
   Compiling term v0.4.6
   Compiling itoa v0.3.4
   Compiling utf8-ranges v1.0.0
   Compiling unicode-xid v0.1.0
   Compiling void v1.0.2
   Compiling log v0.3.8
   Compiling pkg-config v0.3.9
   Compiling bitflags v0.9.1
   Compiling lazy_static v0.2.11
   Compiling num-traits v0.1.40
   Compiling lalrpop-util v0.13.1
   Compiling rustc-demangle v0.1.5
   Compiling synom v0.11.3
   Compiling semver v0.6.0
   Compiling memchr v1.0.2
   Compiling rand v0.3.18
   Compiling proc-macro2 v0.1.5
   Compiling unreachable v1.0.0
   Compiling backtrace-sys v0.1.16
   Compiling strings v0.1.1
   Compiling glib-sys v0.4.0 (https://github.com/gtk-rs/sys#b08fc0e1)
   Compiling gobject-sys v0.4.0 (https://github.com/gtk-rs/sys#b08fc0e1)
   Compiling syn v0.11.11
   Compiling aho-corasick v0.6.3
   Compiling rustc_version v0.2.1
   Compiling thread_local v0.3.4
   Compiling quote v0.3.15 (https://github.com/dtolnay/quote#07deeb57)
   Compiling regex v0.2.2
   Compiling extprim v1.4.0
   Compiling synom v0.11.3 (https://github.com/dtolnay/syn#302afd28)
   Compiling serde_derive_internals v0.17.0
   Compiling syn v0.11.11 (https://github.com/dtolnay/syn#302afd28)
   Compiling glib v0.3.1 (https://github.com/gtk-rs/glib#4ba0412b)
   Compiling serde_derive v1.0.21
   Compiling env_logger v0.4.3
   Compiling backtrace v0.3.4
   Compiling error-chain v0.11.0
   Compiling serde v1.0.21
   Compiling toml v0.4.5
   Compiling syntex_pos v0.59.1
   Compiling serde_json v1.0.6
   Compiling syntex_errors v0.59.1
   Compiling syntex_syntax v0.59.1
   Compiling gobject-gen v0.1.0 (file:///home/user/projects/rust/gnome-class)
error[E0495]: cannot infer an appropriate lifetime due to conflicting requirements
   --> src/hir/mod.rs:202:20
    |
202 |         self.items.values()
    |                    ^^^^^^
    |
note: first, the lifetime cannot outlive the lifetime 'ast as defined on the impl at 113:1...
   --> src/hir/mod.rs:113:1
    |
113 | / impl<'ast> Classes<'ast> {
114 | |     fn new() -> Classes<'ast> {
115 | |         Classes {
116 | |             items: HashMap::new(),
...   |
203 | |     }
204 | | }
    | |_^
note: ...so that types are compatible (expected &std::collections::HashMap<syn::Ident, hir::Class<'_>>, found &std::collections::HashMap<syn::Ident, hir::Class<'ast>>)
   --> src/hir/mod.rs:202:20
    |
202 |         self.items.values()
    |                    ^^^^^^
    = note: but, the lifetime must be valid for the static lifetime...
note: ...so that types are compatible (expected &hir::Class<'_>, found &'a hir::Class<'static>)
   --> src/hir/mod.rs:201:34
    |
201 |     pub fn iter<'a>(&'a self) -> impl Iterator<Item = &'a Class> + 'a {
    |                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: aborting due to previous error

error: Could not compile `gobject-gen`.

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