[INFO] fetching crate mergui 0.1.0-alpha0.8...
[INFO] testing mergui-0.1.0-alpha0.8 against 1.100.0-beta.1 for beta-1.100-2
[INFO] extracting crate mergui 0.1.0-alpha0.8 into /workspace/builds/worker-1-tc2/source
[INFO] started tweaking crates.io crate mergui 0.1.0-alpha0.8
[INFO] finished tweaking crates.io crate mergui 0.1.0-alpha0.8
[INFO] tweaked toml for crates.io crate mergui 0.1.0-alpha0.8 written to /workspace/builds/worker-1-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate mergui 0.1.0-alpha0.8 on toolchain 1.100.0-beta.1
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.100.0-beta.1" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate crates.io crate mergui 0.1.0-alpha0.8 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.100.0-beta.1" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-m" "1610612736" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:3111399a4047eeb3a02b7a90e478d715f38a8c6669b5c4b49d30a17385265909" "sleep" "infinity", kill_on_drop: false }`
[INFO] [stdout] 3302ecdcb59228ef417ae3fa43d02ce4b298c766ad2f4bf308949b333b06c218
[INFO] running `Command { std: "docker" "start" "3302ecdcb59228ef417ae3fa43d02ce4b298c766ad2f4bf308949b333b06c218", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "3302ecdcb59228ef417ae3fa43d02ce4b298c766ad2f4bf308949b333b06c218", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "exec" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-w" "/opt/rustwide/workdir" "--user" "0:0" "3302ecdcb59228ef417ae3fa43d02ce4b298c766ad2f4bf308949b333b06c218" "/opt/rustwide/cargo-home/bin/cargo" "+1.100.0-beta.1" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "3302ecdcb59228ef417ae3fa43d02ce4b298c766ad2f4bf308949b333b06c218", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "exec" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-w" "/opt/rustwide/workdir" "--user" "0:0" "3302ecdcb59228ef417ae3fa43d02ce4b298c766ad2f4bf308949b333b06c218" "/opt/rustwide/cargo-home/bin/cargo" "+1.100.0-beta.1" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr]    Compiling cfg-if v0.1.10
[INFO] [stderr]    Compiling xml-rs v0.8.3
[INFO] [stderr]    Compiling log v0.4.11
[INFO] [stderr]    Compiling libc v0.2.80
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]    Compiling khronos_api v3.1.0
[INFO] [stderr]    Compiling byteorder v1.3.4
[INFO] [stderr]    Compiling proc-macro2 v0.4.30
[INFO] [stderr]    Compiling unicode-xid v0.1.0
[INFO] [stderr]    Compiling slab v0.4.2
[INFO] [stderr]    Compiling nix v0.14.1
[INFO] [stderr]    Compiling proc-macro2 v1.0.24
[INFO] [stderr]    Compiling libloading v0.6.5
[INFO] [stderr]    Compiling void v1.0.2
[INFO] [stderr]    Compiling unicode-xid v0.2.1
[INFO] [stderr]    Compiling dlib v0.4.2
[INFO] [stderr]    Compiling lazycell v1.3.0
[INFO] [stderr]    Compiling syn v1.0.52
[INFO] [stderr]    Compiling wayland-sys v0.23.6
[INFO] [stderr]    Compiling stb_truetype v0.3.1
[INFO] [stderr]    Compiling net2 v0.2.36
[INFO] [stderr]    Compiling iovec v0.1.4
[INFO] [stderr]    Compiling quote v0.6.13
[INFO] [stderr]    Compiling wayland-scanner v0.23.6
[INFO] [stderr]    Compiling mio v0.6.22
[INFO] [stderr]    Compiling gl_generator v0.14.0
[INFO] [stderr]    Compiling ordered-float v1.1.0
[INFO] [stderr]    Compiling approx v0.3.2
[INFO] [stderr]    Compiling quote v1.0.7
[INFO] [stderr]    Compiling rusttype v0.8.3
[INFO] [stderr]    Compiling maybe-uninit v2.0.0
[INFO] [stderr]    Compiling pkg-config v0.3.19
[INFO] [stderr]    Compiling num-integer v0.1.44
[INFO] [stderr]    Compiling mio-extras v2.0.6
[INFO] [stderr]    Compiling same-file v1.0.6
[INFO] [stderr]    Compiling x11-dl v2.18.5
[INFO] [stderr]    Compiling downcast-rs v1.2.0
[INFO] [stderr]    Compiling walkdir v2.3.1
[INFO] [stderr]    Compiling rusttype v0.7.9
[INFO] [stderr]    Compiling line_drawing v0.7.0
[INFO] [stderr]    Compiling gl_generator v0.13.1
[INFO] [stderr]    Compiling smallvec v1.5.0
[INFO] [stderr]    Compiling adler32 v1.2.0
[INFO] [stderr]    Compiling scopeguard v1.1.0
[INFO] [stderr]    Compiling crc32fast v1.2.1
[INFO] [stderr]    Compiling xdg v2.2.0
[INFO] [stderr]    Compiling cc v1.0.65
[INFO] [stderr]    Compiling once_cell v1.5.2
[INFO] [stderr]    Compiling andrew v0.2.1
[INFO] [stderr]    Compiling futures-task v0.3.8
[INFO] [stderr]    Compiling parking_lot_core v0.7.2
[INFO] [stderr]    Compiling glow v0.4.0
[INFO] [stderr]    Compiling wayland-client v0.23.6
[INFO] [stderr]    Compiling wayland-protocols v0.23.6
[INFO] [stderr]    Compiling lock_api v0.3.4
[INFO] [stderr]    Compiling glutin_egl_sys v0.1.5
[INFO] [stderr]    Compiling libloading v0.5.2
[INFO] [stderr]    Compiling glutin_glx_sys v0.1.7
[INFO] [stderr]    Compiling memmap v0.7.0
[INFO] [stderr]    Compiling num-rational v0.2.4
[INFO] [stderr]    Compiling num-iter v0.1.42
[INFO] [stderr]    Compiling futures-core v0.3.8
[INFO] [stderr]    Compiling wayland-commons v0.23.6
[INFO] [stderr]    Compiling calloop v0.4.4
[INFO] [stderr]    Compiling parking_lot v0.10.2
[INFO] [stderr]    Compiling inflate v0.4.5
[INFO] [stderr]    Compiling deflate v0.7.20
[INFO] [stderr]    Compiling raw-window-handle v0.3.3
[INFO] [stderr]    Compiling shared_library v0.1.9
[INFO] [stderr]    Compiling instant v0.1.9
[INFO] [stderr]    Compiling hashbrown v0.7.2
[INFO] [stderr]    Compiling percent-encoding v2.1.0
[INFO] [stderr]    Compiling tinyvec_macros v0.1.0
[INFO] [stderr]    Compiling tinyvec v1.1.0
[INFO] [stderr]    Compiling png v0.15.3
[INFO] [stderr]    Compiling osmesa-sys v0.1.2
[INFO] [stderr]    Compiling jpeg-decoder v0.1.20
[INFO] [stderr]    Compiling ahash v0.3.8
[INFO] [stderr]    Compiling unicode-normalization v0.1.16
[INFO] [stderr]    Compiling indexmap v1.6.0
[INFO] [stderr]    Compiling image v0.22.5
[INFO] [stderr]    Compiling bytemuck v1.4.1
[INFO] [stderr]    Compiling mint v0.5.6
[INFO] [stderr]    Compiling golem v0.1.7
[INFO] [stderr]    Compiling elefont v0.1.3
[INFO] [stderr]    Compiling hashbrown v0.9.1
[INFO] [stderr]    Compiling pin-project-internal v1.0.2
[INFO] [stderr]    Compiling pin-project v1.0.2
[INFO] [stderr]    Compiling futures-util v0.3.8
[INFO] [stderr]    Compiling futures-executor v0.3.8
[INFO] [stderr]    Compiling platter v0.1.4
[INFO] [stderr]    Compiling smithay-client-toolkit v0.6.6
[INFO] [stderr]    Compiling winit v0.22.2
[INFO] [stderr]    Compiling glutin v0.24.1
[INFO] [stderr]    Compiling blinds v0.1.6
[INFO] [stderr]    Compiling quicksilver v0.4.0
[INFO] [stderr]    Compiling mergui v0.1.0-alpha0.8 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0277]: a value of type `!` cannot be built from an iterator over elements of type `()`
[INFO] [stdout]    --> src/widgets/dropdown.rs:207:28
[INFO] [stdout]     |
[INFO] [stdout] 207 |                 .collect::<Result<_>>()?;
[INFO] [stdout]     |                  -------   ^^^^^^^^^ value of type `!` cannot be built from `std::iter::Iterator<Item=()>`
[INFO] [stdout]     |                  |
[INFO] [stdout]     |                  required by a bound introduced by this call
[INFO] [stdout]     |
[INFO] [stdout]     = help: the trait `FromIterator<()>` is not implemented for `!`
[INFO] [stdout] help: the trait `FromIterator<Result<T, E>>` is conditionally implemented for `Result<V, E>`
[INFO] [stdout]    --> /rustc/e3feeb59cd1bdd011a2bfcc0747b55125d9b8527/library/core/src/result.rs:2114:14
[INFO] [stdout]     |
[INFO] [stdout]     = note: unsatisfied requirement introduced here: `!: FromIterator<()>`
[INFO] [stdout]     = note: this error might have been caused by changes to Rust's type-inference algorithm (see issue #148922 <https://github.com/rust-lang/rust/issues/148922> for more information)
[INFO] [stdout]     = help: you might have intended to use the type `()` here instead
[INFO] [stdout]     = note: required for `Result<!, QuicksilverError>` to implement `FromIterator<Result<(), QuicksilverError>>`
[INFO] [stdout] note: required by a bound in `collect`
[INFO] [stdout]    --> /rustc/e3feeb59cd1bdd011a2bfcc0747b55125d9b8527/library/core/src/iter/traits/iterator.rs:2087:4
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0277`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `mergui` (lib) due to 1 previous error
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "3302ecdcb59228ef417ae3fa43d02ce4b298c766ad2f4bf308949b333b06c218", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3302ecdcb59228ef417ae3fa43d02ce4b298c766ad2f4bf308949b333b06c218", kill_on_drop: false }`
[INFO] [stdout] 3302ecdcb59228ef417ae3fa43d02ce4b298c766ad2f4bf308949b333b06c218
