`./x.py check` failed if incremental builds enabled

[kenta7777]

This error occurred when running ./x.py check.
Should I remove these unused attributes?

$ ./x.py check
Updating only changed submodules
Submodules updated in 0.04 seconds
    Finished dev [unoptimized] target(s) in 0.58s
Checking rustdoc artifacts (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu)
Checking std artifacts (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu)
    Checking core v0.0.0 (/home/kenta/rust/src/libcore)
error: unused attribute=======================>                        ] 21/36: core                    
   --> src/libcore/num/mod.rs:50:17
    |
50  |                   #[rustc_layout_scalar_valid_range_start(1)]
    |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...
100 | / nonzero_integers! {
101 | |     #[stable(feature = "nonzero", since = "1.28.0")] NonZeroU8(u8);
102 | |     #[stable(feature = "nonzero", since = "1.28.0")] NonZeroU16(u16);
103 | |     #[stable(feature = "nonzero", since = "1.28.0")] NonZeroU32(u32);
...   |
112 | |     #[stable(feature = "signed_nonzero", since = "1.34.0")] NonZeroIsize(isize);
113 | | }
    | |_- in this macro invocation
    |
    = note: `-D unused-attributes` implied by `-D warnings`

error: unused attribute
   --> src/libcore/num/mod.rs:50:17
    |
50  |                   #[rustc_layout_scalar_valid_range_start(1)]
    |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...
100 | / nonzero_integers! {
101 | |     #[stable(feature = "nonzero", since = "1.28.0")] NonZeroU8(u8);
102 | |     #[stable(feature = "nonzero", since = "1.28.0")] NonZeroU16(u16);
103 | |     #[stable(feature = "nonzero", since = "1.28.0")] NonZeroU32(u32);
...   |
112 | |     #[stable(feature = "signed_nonzero", since = "1.34.0")] NonZeroIsize(isize);
113 | | }
    | |_- in this macro invocation

error: unused attribute
    --> src/libcore/ptr.rs:2721:1
     |
2721 | #[rustc_layout_scalar_valid_range_start(1)]
     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: unused attribute
    --> src/libcore/ptr.rs:2879:1
     |
2879 | #[rustc_layout_scalar_valid_range_start(1)]
     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: unused attribute
  --> src/libcore/ops/function.rs:59:1
   |
59 | / #[rustc_on_unimplemented(
60 | |     on(Args="()", note="wrap the `{Self}` in a closure with no arguments: `|| {{ /* code */ }}"),
61 | |     message="expected a `{Fn}<{Args}>` closure, found `{Self}`",
62 | |     label="expected an `Fn<{Args}>` closure, found `{Self}`",
63 | | )]
   | |__^

error: unused attribute
   --> src/libcore/ops/function.rs:138:1
    |
138 | / #[rustc_on_unimplemented(
139 | |     on(Args="()", note="wrap the `{Self}` in a closure with no arguments: `|| {{ /* code */ }}"),
140 | |     message="expected a `{FnMut}<{Args}>` closure, found `{Self}`",
141 | |     label="expected an `FnMut<{Args}>` closure, found `{Self}`",
142 | | )]
    | |__^

error: unused attribute
   --> src/libcore/ops/function.rs:217:1
    |
217 | / #[rustc_on_unimplemented(
218 | |     on(Args="()", note="wrap the `{Self}` in a closure with no arguments: `|| {{ /* code */ }}"),
219 | |     message="expected a `{FnOnce}<{Args}>` closure, found `{Self}`",
220 | |     label="expected an `FnOnce<{Args}>` closure, found `{Self}`",
221 | | )]
    | |__^

error: unused attribute
  --> src/libcore/ops/index.rs:53:1
   |
53 | / #[rustc_on_unimplemented(
54 | |     message="the type `{Self}` cannot be indexed by `{Idx}`",
55 | |     label="`{Self}` cannot be indexed by `{Idx}`",
56 | | )]
   | |__^

error: unused attribute
   --> src/libcore/ops/index.rs:143:1
    |
143 | / #[rustc_on_unimplemented(
144 | |     on(
145 | |         _Self="&str",
146 | |         note="you can use `.chars().nth()` or `.bytes().nth()`
...   |
160 | |     label="`{Self}` cannot be mutably indexed by `{Idx}`",
161 | | )]
    | |__^

error: unused attribute
  --> src/libcore/ops/try.rs:8:1
   |
8  | / #[rustc_on_unimplemented(
9  | |    on(all(
10 | |        any(from_method="from_error", from_method="from_ok"),
11 | |        from_desugaring="?"),
...  |
19 | |       label="the `?` operator cannot be applied to type `{Self}`")
20 | | )]
   | |__^

error: unused attribute
   --> src/libcore/cmp.rs:185:1
    |
185 | / #[rustc_on_unimplemented(
186 | |     message="can't compare `{Self}` with `{Rhs}`",
187 | |     label="no implementation for `{Self} == {Rhs}`",
188 | | )]
    | |__^

error: unused attribute
   --> src/libcore/cmp.rs:695:1
    |
695 | / #[rustc_on_unimplemented(
696 | |     message="can't compare `{Self}` with `{Rhs}`",
697 | |     label="no implementation for `{Self} < {Rhs}` and `{Self} > {Rhs}`",
698 | | )]
    | |__^

error: unused attribute
  --> src/libcore/iter/traits/iterator.rs:21:1
   |
21 | / #[rustc_on_unimplemented(
22 | |     on(
23 | |         _Self="[std::ops::Range<Idx>; 1]",
24 | |         label="if you meant to iterate between two values, remove the square brackets",
...  |
87 | |     message="`{Self}` is not an iterator"
88 | | )]
   | |__^

error: unused attribute
  --> src/libcore/iter/traits/collect.rs:93:1
   |
93 | / #[rustc_on_unimplemented(
94 | |     message="a collection of type `{Self}` cannot be built from an iterator \
95 | |              over elements of type `{A}`",
96 | |     label="a collection of type `{Self}` cannot be built from `std::iter::Iterator<Item={A}>`",
97 | | )]
   | |__^

error: aborting due to 14 previous errors

error: Could not compile `core`.

To learn more, run the command again with --verbose.
command did not execute successfully: "/home/kenta/rust/build/x86_64-unknown-linux-gnu/stage0/bin/cargo" "check" "--target" "x86_64-unknown-linux-gnu" "-j" "4" "--release" "--features" "panic-unwind backtrace" "--manifest-path" "/home/kenta/rust/src/libstd/Cargo.toml" "--message-format" "json"
expected success, got: exit code: 101
failed to run: /home/kenta/rust/build/bootstrap/debug/bootstrap check
Build completed unsuccessfully in 0:00:15

[jonas-schievink]

What's your config.toml? These should only warn, not error.

[kenta7777]

This is a part of my config.toml which is not commented out.

# Indicates whether the LLVM assertions are enabled or not
assertions = true

# Number of codegen units to use for each compiler invocation. A value of 0
# means "the number of cores on this machine", and 1+ is passed through to the
# compiler.
codegen-units = 0

# Sets the number of codegen units to build the standard library with,
# regardless of what the codegen-unit setting for the rest of the compiler is.
#codegen-units-std = 1

# Whether or not debug assertions are enabled for the compiler and standard
# library. Also enables compilation of debug! and trace! logging macros.
debug-assertions = true

# Whether or not debuginfo is emitted
debuginfo = true

# Whether or not line number debug information is emitted
debuginfo-lines = true

# Whether to always use incremental compilation when building rustc
incremental = true

[varkor]

If you run x.py clean and check again, these warnings should go away. It would be nice if this wasn't necessary, though.

[kenta7777]

@varkor Thank you for your advice! ./x.py clean and then build completed successfully!

[timvermeulen]

This happens to me every time I try to do an incremental build after making a change. Is there any other way to resolve this than x.py clean?

[varkor]

Let's keep this issue open, because we'd rather not have to clean even single time.

[mark-i-m]

I'm running into the same problem with incremental builds, which makes incremental kind of useless...

[pnkfelix]

I think I am also running into this. I'm going to tag this T-compiler to try to increase visibility