Compilation Error: *const i8 cannot be sent between threads safely

[scull7]

I'm getting a compilation failure when pulling in oracle. I've tried using the master branch:

oracle = { git = "https://github.com/kubo/rust-oracle.git", features = ["chrono"] }

And version 0.3.1:

oracle = { version = "0.3.1", features = ["chrono"] }

rustc version:

stable-x86_64-apple-darwin unchanged - rustc 1.39.0 (4560ea788 2019-11-04)

error[E0277]: `*const i8` cannot be sent between threads safely
   --> /Users/nathansculli/.cargo/git/checkouts/rust-oracle-858dd8ce065f6a17/2e61902/src/lib.rs:411:1
    |
411 | / lazy_static! {
412 | |     static ref DPI_CONTEXT: ContextResult = {
413 | |         let mut ctxt = Context {
414 | |             context: ptr::null_mut(),
...   |
449 | |     };
450 | | }
    | |_^ `*const i8` cannot be sent between threads safely
    |
    = help: within `ContextResult`, the trait `std::marker::Send` is not implemented for `*const i8`
    = note: required because it appears within the type `binding::dpiErrorInfo`
    = note: required because it appears within the type `ContextResult`
    = note: required because of the requirements on the impl of `std::marker::Sync` for `spin::once::Once<ContextResult>`
    = note: required because it appears within the type `lazy_static::lazy::Lazy<ContextResult>`
    = note: shared static variables must have a type that implements `Sync`
    = note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)

error: aborting due to previous error

For more information about this error, try `rustc --explain E0277`.
error: could not compile `oracle`.

[scull7]

I've also tried to compile without enabling the "chrono" feature, I receive the same error.

[mexus]

Can't reproduce on rustc 1.39.0 on linux; could it be some mac-related issue?

[kubo]

@scull7
I could not reproduced the issue on Linux and macOS.

$ rustup toolchain list
stable-x86_64-apple-darwin (default)
$ rustc --version
rustc 1.39.0 (4560ea788 2019-11-04)
$ cargo new oracle-app
     Created binary (application) `oracle-app` package
$ cd oracle-app/
$ echo 'oracle = { git = "https://github.com/kubo/rust-oracle.git", features = ["chrono"] }' >> Cargo.toml 
$ cargo build
    Updating git repository `https://github.com/kubo/rust-oracle.git`
    Updating crates.io index
  Downloaded chrono v0.4.9
  Downloaded autocfg v0.1.7
  Downloaded num-traits v0.2.9
   Compiling proc-macro2 v1.0.6
   Compiling autocfg v0.1.7
   Compiling unicode-xid v0.2.0
   Compiling syn v1.0.8
   Compiling libc v0.2.65
   Compiling cc v1.0.47
   Compiling lazy_static v1.4.0
   Compiling try_from v0.2.2
   Compiling num-traits v0.2.9
   Compiling num-integer v0.1.41
   Compiling quote v1.0.2
   Compiling time v0.1.42
   Compiling oracle v0.3.1 (https://github.com/kubo/rust-oracle.git#2e619029)
   Compiling chrono v0.4.9
   Compiling proc-macro-hack v0.5.11
   Compiling paste-impl v0.1.6
   Compiling paste v0.1.6
   Compiling oracle-app v0.1.0 (/Users/kubo/oracle-app)
    Finished dev [unoptimized + debuginfo] target(s) in 46.33s

Could you paste the contents of Cargo.lock to gist and post the link? I want to know the exact depending crate versions on your environment.

[scull7]

Here's my Cargo.lock file: https://gist.github.com/scull7/41be1d15360258d351c5658cef90247a

[scull7]

Is anyone able to shed some light on this? Still stuck.

[kubo]

I found that the error appeared when oracle is used with tracing-core >= 0.1.4 (after this commit). I don't know why.

I'll add unsafe impl Send for ContextResult {} in src/lib.rs for workaround.

[scull7]

Thank you 🙏