[INFO] fetching crate lettre_email 0.9.0...
[INFO] extracting crate lettre_email 0.9.0 into work/ex/pr-61629/sources/master#c8865d8e195813ade6b84434ac9f8850e7112d1a/reg/lettre_email/0.9.0
[INFO] extracting crate lettre_email 0.9.0 into work/ex/pr-61629/sources/try#e212b7d492c96d3837691ba29d32d5f468933fb8/reg/lettre_email/0.9.0
[INFO] validating manifest of lettre_email-0.9.0 on toolchain master#c8865d8e195813ade6b84434ac9f8850e7112d1a
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+c8865d8e195813ade6b84434ac9f8850e7112d1a-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of lettre_email-0.9.0 on toolchain try#e212b7d492c96d3837691ba29d32d5f468933fb8
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+e212b7d492c96d3837691ba29d32d5f468933fb8-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing lettre_email-0.9.0
[INFO] finished frobbing lettre_email-0.9.0
[INFO] frobbed toml for lettre_email-0.9.0 written to work/ex/pr-61629/sources/master#c8865d8e195813ade6b84434ac9f8850e7112d1a/reg/lettre_email/0.9.0/Cargo.toml
[INFO] started frobbing lettre_email-0.9.0
[INFO] finished frobbing lettre_email-0.9.0
[INFO] frobbed toml for lettre_email-0.9.0 written to work/ex/pr-61629/sources/try#e212b7d492c96d3837691ba29d32d5f468933fb8/reg/lettre_email/0.9.0/Cargo.toml
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+c8865d8e195813ade6b84434ac9f8850e7112d1a-alt" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+e212b7d492c96d3837691ba29d32d5f468933fb8-alt" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+c8865d8e195813ade6b84434ac9f8850e7112d1a-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+e212b7d492c96d3837691ba29d32d5f468933fb8-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] building lettre_email-0.9.0 against try#e212b7d492c96d3837691ba29d32d5f468933fb8 for pr-61629
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-61629/worker-1/try#e212b7d492c96d3837691ba29d32d5f468933fb8:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-61629/sources/try#e212b7d492c96d3837691ba29d32d5f468933fb8/reg/lettre_email/0.9.0:/opt/crater/workdir:ro,Z" "-v" "/mnt/big/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/big/crater/work/local/rustup-home:/opt/crater/rustup-home:ro,Z" "-e" "USER_ID=1000" "-e" "SOURCE_DIR=/opt/crater/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/crater/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/crater/cargo-home" "-e" "RUSTUP_HOME=/opt/crater/rustup-home" "-w" "/opt/crater/workdir" "-m" "1536M" "--network" "none" "rustops/crates-build-env" "/opt/crater/cargo-home/bin/cargo" "+e212b7d492c96d3837691ba29d32d5f468933fb8-alt" "build" "--frozen"`
[INFO] [stdout] 7c61f45b86476bf09b78b37b97f4e8859ef0aff2df93afabaee620566a765c76
[INFO] running `"docker" "start" "-a" "7c61f45b86476bf09b78b37b97f4e8859ef0aff2df93afabaee620566a765c76"`
[INFO] [stderr]    Compiling ascii_utils v0.9.3
[INFO] [stderr]    Compiling email v0.0.20
[INFO] [stderr]    Compiling fast_chemail v0.9.6
[INFO] [stderr]    Compiling lettre v0.9.1
[INFO] [stderr]    Compiling lettre_email v0.9.0 (/opt/crater/workdir)
[INFO] [stderr] error[E0283]: type annotations required: cannot resolve `std::string::String: std::convert::AsRef<_>`
[INFO] [stderr]    --> src/lib.rs:139:66
[INFO] [stderr]     |
[INFO] [stderr] 139 |         self.header(("Content-Type", format!("{}", content_type).as_ref()))
[INFO] [stderr]     |                                                                  ^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0283`.
[INFO] [stderr] error: Could not compile `lettre_email`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "7c61f45b86476bf09b78b37b97f4e8859ef0aff2df93afabaee620566a765c76"`
[INFO] running `"docker" "rm" "-f" "7c61f45b86476bf09b78b37b97f4e8859ef0aff2df93afabaee620566a765c76"`
[INFO] [stdout] 7c61f45b86476bf09b78b37b97f4e8859ef0aff2df93afabaee620566a765c76