Make std::io::copy take Read and Write by value instead of by reference

[est31]

The traits are also implemented on mutable references of types implementing that trait.

The initial goal of this PR is to get a crater run done so that impact of breakage can be estimated, then a decision can be made on #105643.

[rustbot]

r? @thomcc

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[rustbot]

Hey! It looks like you've submitted a new PR for the library teams!

If this PR contains changes to any rust-lang/rust public library APIs then please comment with @rustbot label +T-libs-api -T-libs to tag it appropriately. If this PR contains changes to any unstable APIs please edit the PR description to add a link to the relevant API Change Proposal or create one if you haven't already. If you're unsure where your change falls no worries, just leave it as is and the reviewer will take a look and make a decision to forward on if necessary.

Examples of T-libs-api changes:

• Stabilizing library features
• Introducing insta-stable changes such as new implementations of existing stable traits on existing stable types
• Introducing new or changing existing unstable library APIs (excluding permanently unstable features / features without a tracking issue)
• Changing public documentation in ways that create new stability guarantees
• Changing observable runtime behavior of library APIs

[est31]

@bors try

[bors]

⌛ Trying commit 8a7c47d21d4b3af4bb15c663615a6fac7bb8c32d with merge 57441dc4961028bc64c66456cc33e98669c830a9...

[est31]

@bors try

[bors]

⌛ Trying commit d63f5ff4dc0993baa817f360ba578eec0374d36e with merge 5cc6cc22f274979bcd2a65b62b719ae3a4f42519...

[bors]

💔 Test failed - checks-actions

[est31]

This has a good start... 😆

 Documenting stage2 cargo (x86_64-unknown-linux-gnu)
[...]
    Checking gix-odb v0.42.0
error[E0382]: borrow of moved value: `buf`
  --> /cargo/registry/src/index.crates.io-6f17d22bba15001f/gix-config-0.18.0/src/file/init/from_paths.rs:71:13
   |
57 |         buf: &mut Vec<u8>,
   |         --- move occurs because `buf` has type `&mut Vec<u8>`, which does not implement the `Copy` trait
...
71 |             buf.clear();
   |             ^^^^^^^^^^^ value borrowed here after move
...
78 |                 buf,
   |                 --- value moved here, in previous iteration of loop

error[E0382]: borrow of moved value: `buf`
   --> /cargo/registry/src/index.crates.io-6f17d22bba15001f/gix-config-0.18.0/src/file/includes/mod.rs:101:9
    |
88  |     buf: &mut Vec<u8>,
    |     --- move occurs because `buf` has type `&mut Vec<u8>`, which does not implement the `Copy` trait
89  | ) -> Result<(), Error> {
90  |     for (section_id, config_path) in section_ids_and_include_paths {
    |     -------------------------------------------------------------- inside of this loop
...
101 |         buf.clear();
    |         ^^^^^^^^^^^ value borrowed here after move
102 |         std::io::copy(&mut std::fs::File::open(&config_path)?, buf)?;
    |                                                                --- value moved here, in previous iteration of loop

[rustbot]

Some changes occurred in src/tools/cargo

cc @ehuss

[est31]

@bors try

[bors]

⌛ Trying commit 8ea0e58e58d1f65761c3ee23802b37d9daf77ff1 with merge 98822f45d8d7b85b11ab1d06265216f1eae4b469...

[bors]

💔 Test failed - checks-actions

[est31]

@bors try

[bors]

⌛ Trying commit bebcd5866b468f95748402852fde98f130e346ca with merge 275392a4242c37cea20935e91a1f83a43ce59ccc...

[bors]

💔 Test failed - checks-actions

[est31]

@bors try

[bors]

⌛ Trying commit 81617fe with merge a326ccb4ce868265c4f69a0270f3033164acc4f9...

[bors]

☀️ Try build successful - checks-actions
Build commit: a326ccb4ce868265c4f69a0270f3033164acc4f9 (a326ccb4ce868265c4f69a0270f3033164acc4f9)

[Amanieu]

@craterbot check

[craterbot]

👌 Experiment pr-111063 created and queued.
🤖 Automatically detected try build a326ccb4ce868265c4f69a0270f3033164acc4f9
🔍 You can check out the queue and this experiment's details.

ℹ️ Crater is a tool to run experiments across parts of the Rust ecosystem. Learn more

[craterbot]

🚧 Experiment pr-111063 is now running

ℹ️ Crater is a tool to run experiments across parts of the Rust ecosystem. Learn more

[craterbot]

🎉 Experiment pr-111063 is completed!
📊 1091 regressed and 3 fixed (266148 total)
📰 Open the full report.

⚠️ If you notice any spurious failure please add them to the blacklist!
ℹ️ Crater is a tool to run experiments across parts of the Rust ecosystem. Learn more

[est31]

It seems that the large impact of a thousand regressed crates is caused by just one crate on its own, exr (in various versions of that crate; 1.4.1, 1.4.2, 1.5.0, 1.5.1, 1.5.2, 1.5.3, 1.6.3). The other regressions are fairly minor. Thankfully the cargo published to crates.io doesn't use gitoxide yet, otherwise all the tools using cargo would be regressed, too.

[Mark-Simulacrum]

@craterbot run mode=check crates=https://crater-reports.s3.amazonaws.com/pr-111063/retry-regressed-list.txt

[craterbot]

🚨 Error: failed to parse the command

🆘 If you have any trouble with Crater please ping @rust-lang/infra!
ℹ️ Crater is a tool to run experiments across parts of the Rust ecosystem. Learn more

[lqd]

@craterbot run mode=check-only crates=https://crater-reports.s3.amazonaws.com/pr-111063/retry-regressed-list.txt

[craterbot]

👌 Experiment pr-111063-1 created and queued.
🤖 Automatically detected try build a326ccb4ce868265c4f69a0270f3033164acc4f9
🔍 You can check out the queue and this experiment's details.

ℹ️ Crater is a tool to run experiments across parts of the Rust ecosystem. Learn more

[craterbot]

🚧 Experiment pr-111063-1 is now running

ℹ️ Crater is a tool to run experiments across parts of the Rust ecosystem. Learn more

[craterbot]

🎉 Experiment pr-111063-1 is completed!
📊 1002 regressed and 0 fixed (1091 total)
📰 Open the full report.

⚠️ If you notice any spurious failure please add them to the blacklist!
ℹ️ Crater is a tool to run experiments across parts of the Rust ecosystem. Learn more

[est31]

Similar results as above, but thankfully now some of the noise got cleaned up.

Some analysis: of the 1002 regressions, 881 are caused by different versions of exr. The remaining 120 are either root regressions (42), or other crates used by those. The biggest two groups are cfb (17 regressions), and various gix crates (21 regressions, but I expect this to increase the time the gix adoption in cargo hits stable).

Sometimes a good suggestion is shown, but most of the time, there is no suggestion.

In general, I think if one wants to patch this, one has to release patched releases for both multiple versions of gix as well as for exr.

[est31]

I've obtained the information that I wanted to obtain with this PR: the results from the crater run. If the libs team decides to go towards the direction of doing this, then we can open a new PR that isn't as full with bot spam as this one :).