[Pkg-rust-maintainers] Bug#988025: rust-rustyline FTBFS in buster: error[E0283]: type annotations needed

[Adrian Bunk]

Source: rust-rustyline
Version: 3.0.0-2
Severity: serious
Tags: ftbfs
Control: close -1 6.3.0-2

https://tests.reproducible-builds.org/debian/rb-pkg/buster/amd64/rust-rustyline.html

...
error[E0283]: type annotations needed for `std::result::Result<std::string::String, error::ReadlineError>`
   --> src/lib.rs:655:43
    |
652 |     let user_input = readline_edit(prompt, initial, editor, &original_mode);
    |         ---------- consider giving `user_input` the explicit type `std::result::Result<std::string::String, error::ReadlineError>`, where the type parameter `std::string::String` is specified
...
655 |             editor.add_history_entry(line.as_ref());
    |                                           ^^^^^^ cannot infer type for struct `std::string::String`
    |
    = note: cannot resolve `std::string::String: std::convert::AsRef<_>`

error[E0283]: type annotations needed for `std::result::Result<std::string::String, std::io::Error>`
   --> src/history.rs:151:28
    |
150 |         for line in rdr.lines() {
    |                     ----------- the element type for this iterator is not specified
151 |             self.add(line?.as_ref()); // TODO truncate to MAX_LINE
    |                            ^^^^^^ cannot infer type for struct `std::string::String`
    |
    = note: cannot resolve `std::string::String: std::convert::AsRef<_>`

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0283`.
error: could not compile `rustyline`.

Caused by:
  process didn't exit successfully: `CARGO_PKG_VERSION_PATCH=0 CARGO_PKG_VERSION_PRE= CARGO_PKG_VERSION=3.0.0 CARGO_MANIFEST_DIR=/build/rust-rustyline-3.0.0 CARGO_PKG_DESCRIPTION='Rustyline, a readline implementation based on Antirez'\''s Linenoise' CARGO_PKG_VERSION_MINOR=0 CARGO_PKG_REPOSITORY='https://github.com/kkawakam/rustyline' CARGO_PKG_NAME=rustyline CARGO_PKG_HOMEPAGE= LD_LIBRARY_PATH='/build/rust-rustyline-3.0.0/target/debug/deps:/usr/lib' CARGO=/usr/bin/cargo CARGO_PKG_VERSION_MAJOR=3 CARGO_PKG_AUTHORS='Katsu Kawakami <kkawa1570 at gmail.com>' rustc --crate-name rustyline --edition=2018 src/lib.rs --error-format=json --json=diagnostic-rendered-ansi --crate-type lib --emit=dep-info,metadata,link -C debuginfo=2 -C metadata=32abff220ca5c579 -C extra-filename=-32abff220ca5c579 --out-dir /build/rust-rustyline-3.0.0/target/x86_64-unknown-linux-gnu/debug/deps --target x86_64-unknown-linux-gnu -C incremental=/build/rust-rustyline-3.0.0/target/x86_64-unknown-linux-gnu/debug/incremental -L dependency=/build/rust-rustyline-3.0.0/target/x86_64-unknown-linux-gnu/debug/deps -L dependency=/build/rust-rustyline-3.0.0/target/debug/deps --extern dirs=/build/rust-rustyline-3.0.0/target/x86_64-unknown-linux-gnu/debug/deps/libdirs-3618faff0f4e3e8a.rmeta --extern libc=/build/rust-rustyline-3.0.0/target/x86_64-unknown-linux-gnu/debug/deps/liblibc-30ef7acb640b5e2e.rmeta --extern log=/build/rust-rustyline-3.0.0/target/x86_64-unknown-linux-gnu/debug/deps/liblog-01386711f39997a6.rmeta --extern memchr=/build/rust-rustyline-3.0.0/target/x86_64-unknown-linux-gnu/debug/deps/libmemchr-02ce6f465c2e372b.rmeta --extern nix=/build/rust-rustyline-3.0.0/target/x86_64-unknown-linux-gnu/debug/deps/libnix-43ba8d79152793eb.rmeta --extern unicode_segmentation=/build/rust-rustyline-3.0.0/target/x86_64-unknown-linux-gnu/debug/deps/libunicode_segmentation-97a478139854cbcd.rmeta --extern unicode_width=/build/rust-rustyline-3.0.0/target/x86_64-unknown-linux-gnu/debug/deps/libunicode_width-46fd8893216b9fa2.rmeta --extern utf8parse=/build/rust-rustyline-3.0.0/target/x86_64-unknown-linux-gnu/debug/deps/libutf8parse-f0f585e732c9e7cd.rmeta -C debuginfo=2 --cap-lints warn -C linker=x86_64-linux-gnu-gcc -C link-arg=-Wl,-z,relro --remap-path-prefix /build/rust-rustyline-3.0.0=/usr/share/cargo/registry/rustyline-3.0.0` (exit code: 1)
warning: build failed, waiting for other jobs to finish...
error: build failed
dh_auto_test: /usr/share/cargo/bin/cargo build returned exit code 101
make: *** [debian/rules:3: build] Error 25