"method backtrace is not a member of trait StdError"

[Berrysoft]

In recent nightly std, the trait std::error::Error doesn't contain method backtrace, which makes anyhow fail to compile. Actually the rust-analyzer complains.

[dtolnay]

Since you mentioned rust-analyzer, I'm guessing this is a duplicate of #250.

[Berrysoft]

Not exactly. It reports different error:

[ERROR rust_analyzer::lsp_utils] failed to run build scripts

error[E0407]: method `backtrace` is not a member of trait `StdError`
   --> C:\Users\Straw\.cargo\registry\src\github.jparrowsec.cn-1ecc6299db9ec823\anyhow-1.0.61\src\context.rs:127:5
    |
127 | /     fn backtrace(&self) -> Option<&Backtrace> {
128 | |         self.error.backtrace()
129 | |     }
    | |_____^ not a member of trait `StdError`


error[E0407]: method `backtrace` is not a member of trait `StdError`
   --> C:\Users\Straw\.cargo\registry\src\github.jparrowsec.cn-1ecc6299db9ec823\anyhow-1.0.61\src\context.rs:141:5
    |
141 | /     fn backtrace(&self) -> Option<&Backtrace> {
142 | |         Some(self.error.backtrace())
143 | |     }
    | |_____^ not a member of trait `StdError`


error[E0407]: method `backtrace` is not a member of trait `StdError`
   --> C:\Users\Straw\.cargo\registry\src\github.jparrowsec.cn-1ecc6299db9ec823\anyhow-1.0.61\src\error.rs:907:5
    |
907 | /     fn backtrace(&self) -> Option<&Backtrace> {
908 | |         Some(unsafe { ErrorImpl::backtrace(self.erase()) })
909 | |     }
    | |_____^ not a member of trait `StdError`


error[E0407]: method `backtrace` is not a member of trait `StdError`
  --> C:\Users\Straw\.cargo\registry\src\github.jparrowsec.cn-1ecc6299db9ec823\anyhow-1.0.61\src\wrapper.rs:71:5
   |
71 | /     fn backtrace(&self) -> Option<&crate::backtrace::Backtrace> {
72 | |         self.0.backtrace()
73 | |     }
   | |_____^ not a member of trait `StdError`


error[E0599]: no method named `backtrace` found for type parameter `E` in the current scope
  --> C:\Users\Straw\.cargo\registry\src\github.jparrowsec.cn-1ecc6299db9ec823\anyhow-1.0.61\src\backtrace.rs:41:20
   |
41 |         match $err.backtrace() {
   |                    ^^^^^^^^^ method not found in `E`
   |
  ::: C:\Users\Straw\.cargo\registry\src\github.jparrowsec.cn-1ecc6299db9ec823\anyhow-1.0.61\src\context.rs:19:10
   |
19 |     impl<E> StdError for E
   |          - method `backtrace` not found for this type parameter
...
27 |             let backtrace = backtrace_if_absent!(self);
   |                             -------------------------- in this macro invocation
   |
   = note: this error originates in the macro `backtrace_if_absent` (in Nightly builds, run with -Z macro-backtrace for more info)


error[E0599]: no method named `backtrace` found for type parameter `E` in the current scope
   --> C:\Users\Straw\.cargo\registry\src\github.jparrowsec.cn-1ecc6299db9ec823\anyhow-1.0.61\src\context.rs:128:20
    |
121 | impl<C, E> StdError for ContextError<C, E>
    |         - method `backtrace` not found for this type parameter
...
128 |         self.error.backtrace()
    |                    ^^^^^^^^^ method not found in `E`


error[E0599]: no method named `backtrace` found for type parameter `E` in the current scope
  --> C:\Users\Straw\.cargo\registry\src\github.jparrowsec.cn-1ecc6299db9ec823\anyhow-1.0.61\src\backtrace.rs:41:20
   |
41 |         match $err.backtrace() {
   |                    ^^^^^^^^^ method not found in `E`
   |
  ::: C:\Users\Straw\.cargo\registry\src\github.jparrowsec.cn-1ecc6299db9ec823\anyhow-1.0.61\src\error.rs:30:16
   |
30 |     pub fn new<E>(error: E) -> Self
   |                - method `backtrace` not found for this type parameter
...
34 |         let backtrace = backtrace_if_absent!(error);
   |                         --------------------------- in this macro invocation
   |
   = note: this error originates in the macro `backtrace_if_absent` (in Nightly builds, run with -Z macro-backtrace for more info)


error[E0599]: no method named `backtrace` found for type parameter `E` in the current scope
   --> C:\Users\Straw\.cargo\registry\src\github.jparrowsec.cn-1ecc6299db9ec823\anyhow-1.0.61\src\backtrace.rs:41:20
    |
41  |         match $err.backtrace() {
    |                    ^^^^^^^^^ method not found in `E`
    |
   ::: C:\Users\Straw\.cargo\registry\src\github.jparrowsec.cn-1ecc6299db9ec823\anyhow-1.0.61\src\error.rs:527:6
    |
527 | impl<E> From<E> for Error
    |      - method `backtrace` not found for this type parameter
...
533 |         let backtrace = backtrace_if_absent!(error);
    |                         --------------------------- in this macro invocation
    |
    = note: this error originates in the macro `backtrace_if_absent` (in Nightly builds, run with -Z macro-backtrace for more info)


error[E0599]: no method named `backtrace` found for reference `&(dyn std::error::Error + Send + Sync + 'static)` in the current scope
   --> C:\Users\Straw\.cargo\registry\src\github.jparrowsec.cn-1ecc6299db9ec823\anyhow-1.0.61\src\error.rs:889:42
    |
889 |                 return Self::error(this).backtrace();
    |                                          ^^^^^^^^^ method not found in `&(dyn std::error::Error + Send + Sync + 'static)`


error[E0599]: no method named `backtrace` found for struct `Box<(dyn std::error::Error + Send + Sync + 'static)>` in the current scope
   --> C:\Users\Straw\.cargo\registry\src\github.jparrowsec.cn-1ecc6299db9ec823\anyhow-1.0.61\src\backtrace.rs:41:20
    |
41  |         match $err.backtrace() {
    |                    ^^^^^^^^^ method not found in `Box<(dyn std::error::Error + Send + Sync + 'static)>`
    |
   ::: C:\Users\Straw\.cargo\registry\src\github.jparrowsec.cn-1ecc6299db9ec823\anyhow-1.0.61\src\kind.rs:113:25
    |
113 |         let backtrace = backtrace_if_absent!(error);
    |                         --------------------------- in this macro invocation
    |
    = note: this error originates in the macro `backtrace_if_absent` (in Nightly builds, run with -Z macro-backtrace for more info)


error[E0599]: no method named `backtrace` found for struct `Box<(dyn std::error::Error + Send + Sync + 'static)>` in the current scope
  --> C:\Users\Straw\.cargo\registry\src\github.jparrowsec.cn-1ecc6299db9ec823\anyhow-1.0.61\src\wrapper.rs:72:16
   |
72 |         self.0.backtrace()
   |                ^^^^^^^^^ method not found in `Box<(dyn std::error::Error + Send + Sync + 'static)>`


error: aborting due to 11 previous errors


Some errors have detailed explanations: E0407, E0599.

For more information about an error, try `rustc --explain E0407`.

error: could not compile `anyhow` due to 12 previous errors

[Berrysoft]

I think you need to write a backtrace() like this:

https://github.com/rust-lang/rust/blob/187654481fd828e495919295369d33827f10e1c4/library/std/src/error.rs#L1543

[dtolnay]

I still think it's the same issue. Rust-analyzer's RUSTC_WRAPPER improperly returns a success exit code on all compiler invocations, even where building should fail. This is rust-lang/rust-analyzer#12973. The exact output you get after this happens depends on whether the toolchain is stable or nightly, but that isn't the cause of the failure.

[dtolnay]

If it's the same issue, doing a cargo build outside of rust-analyzer should succeed.

[Berrysoft]

You're right, cargo build succeeded.