Gauge usage of FnOnce::Output in the wild

[compiler-errors]

I'm curious what crates are using FnOnce::Output directly. Let's run crater to see.

I downloaded all crates with get-all-crates --latest then used zgrep to grep for ::Output, which may or may not be any of the traits in std::ops, though it did majorly cut down on the crates we'll crater: https://gist.githubusercontent.com/compiler-errors/1ef63d6e086d9a5915fb510dafdfdd43/raw/86e3bac4235e667c4c2cdf2a21d52ca38567ab1a/gistfile1.txt

r? @ghost

[compiler-errors]

@bors try

[bors]

⌛ Trying commit d9d6fbf with merge dd5bcc8...

[bors]

💔 Test failed - checks-actions

[compiler-errors]

@bors try

[bors]

⌛ Trying commit a7e10ca with merge 34c3b22...

[rust-log-analyzer]

The job x86_64-gnu-tools failed! Check out the build log: (web) (plain)

Click to see the possible cause of the failure (guessed by this bot)

   Compiling rustc_middle v0.0.0 (/checkout/compiler/rustc_middle)
error: unused import: `LOCAL_CRATE`
  --> compiler/rustc_middle/src/middle/stability.rs:15:59
   |
15 | use rustc_hir::def_id::{DefId, LocalDefId, LocalDefIdMap, LOCAL_CRATE};
   |
   = note: `-D unused-imports` implied by `-D warnings`
   = help: to override `-D warnings` add `#[allow(unused_imports)]`

[rust-log-analyzer]

The job dist-x86_64-linux failed! Check out the build log: (web) (plain)

Click to see the possible cause of the failure (guessed by this bot)

file:.git/config remote.origin.url=https://github.com/rust-lang-ci/rust
file:.git/config remote.origin.fetch=+refs/heads/*:refs/remotes/origin/*
file:.git/config gc.auto=0
file:.git/config http.https://github.com/.extraheader=AUTHORIZATION: basic ***
file:.git/config branch.try.remote=origin
file:.git/config branch.try.merge=refs/heads/try
file:.git/config submodule.library/backtrace.url=https://github.com/rust-lang/backtrace-rs.git
file:.git/config submodule.library/stdarch.active=true
file:.git/config submodule.library/stdarch.url=https://github.com/rust-lang/stdarch.git
file:.git/config submodule.src/doc/book.active=true
---
[RUSTC-TIMING] wasmparser test:false 24.265
error: unused import: `LOCAL_CRATE`
  --> compiler/rustc_middle/src/middle/stability.rs:15:59
   |
15 | use rustc_hir::def_id::{DefId, LocalDefId, LocalDefIdMap, LOCAL_CRATE};
   |
   = note: `-D unused-imports` implied by `-D warnings`
   = help: to override `-D warnings` add `#[allow(unused_imports)]`

---
Caused by:
    Command RUST_BACKTRACE=full python3 /checkout/x.py build --target x86_64-unknown-linux-gnu --host x86_64-unknown-linux-gnu --stage 2 library/std --rust-profile-generate /tmp/tmp-multistage/opt-artifacts/rustc-pgo --set llvm.thin-lto=false --set llvm.link-shared=true [at /checkout/obj] has failed with exit code Some(1)

Stack backtrace:
   0: <anyhow::Error>::msg::<alloc::string::String>
             at /rust/deps/anyhow-1.0.86/src/backtrace.rs:27:14
   1: <opt_dist::exec::CmdBuilder>::run
             at /rustc/34c3b22e5aece7b832201306c4ae3bfcfe6122f7/src/tools/opt-dist/src/exec.rs:78:17
   2: <opt_dist::exec::Bootstrap>::run
             at /rustc/34c3b22e5aece7b832201306c4ae3bfcfe6122f7/src/tools/opt-dist/src/exec.rs:179:9
             at /rustc/34c3b22e5aece7b832201306c4ae3bfcfe6122f7/src/tools/opt-dist/src/main.rs:225:13
             at /rustc/34c3b22e5aece7b832201306c4ae3bfcfe6122f7/src/tools/opt-dist/src/main.rs:225:13
   4: <opt_dist::timer::TimerSection>::section::<opt_dist::execute_pipeline::{closure#1}::{closure#0}, ()>
             at /rustc/34c3b22e5aece7b832201306c4ae3bfcfe6122f7/src/tools/opt-dist/src/timer.rs:111:22
             at /rustc/34c3b22e5aece7b832201306c4ae3bfcfe6122f7/src/tools/opt-dist/src/main.rs:214:9
             at /rustc/34c3b22e5aece7b832201306c4ae3bfcfe6122f7/src/tools/opt-dist/src/main.rs:214:9
   6: <opt_dist::timer::TimerSection>::section::<opt_dist::execute_pipeline::{closure#1}, opt_dist::training::RustcPGOProfile>
             at /rustc/34c3b22e5aece7b832201306c4ae3bfcfe6122f7/src/tools/opt-dist/src/timer.rs:111:22
             at /rustc/34c3b22e5aece7b832201306c4ae3bfcfe6122f7/src/tools/opt-dist/src/main.rs:211:29
   8: opt_dist::main
             at /rustc/34c3b22e5aece7b832201306c4ae3bfcfe6122f7/src/tools/opt-dist/src/main.rs:401:18
   9: <fn() -> core::result::Result<(), anyhow::Error> as core::ops::function::FnOnce<()>>::call_once
   9: <fn() -> core::result::Result<(), anyhow::Error> as core::ops::function::FnOnce<()>>::call_once
             at /rustc/75ac3b6331873133c4f7a10f2252afd6f3906c6a/library/core/src/ops/function.rs:250:5
  10: std::sys_common::backtrace::__rust_begin_short_backtrace::<fn() -> core::result::Result<(), anyhow::Error>, core::result::Result<(), anyhow::Error>>
             at /rustc/75ac3b6331873133c4f7a10f2252afd6f3906c6a/library/std/src/sys_common/backtrace.rs:155:18
  11: std::rt::lang_start::<core::result::Result<(), anyhow::Error>>::{closure#0}
             at /rustc/75ac3b6331873133c4f7a10f2252afd6f3906c6a/library/std/src/rt.rs:159:18
  12: core::ops::function::impls::<impl core::ops::function::FnOnce<A> for &F>::call_once
  13: std::panicking::try::do_call
             at /rustc/75ac3b6331873133c4f7a10f2252afd6f3906c6a/library/std/src/panicking.rs:559:40
  14: std::panicking::try
             at /rustc/75ac3b6331873133c4f7a10f2252afd6f3906c6a/library/std/src/panicking.rs:523:19

[bors]

💔 Test failed - checks-actions

[compiler-errors]

Actually I literally don't care if people are using FnOnce::Output in the wild lmao