[issue?] fail compile in rust 1.43.0

[Stvchm9703]

environment

rustc 1.43.0-nightly (d3c79346a 2020-02-29)
window 10

###what is going on
I just used the tonic library to build my server,
then I updated my compile, and it raised this error

A:\Gitrepo\unlight-zwei-game-duel-service>cargo run
   Compiling tower-balance v0.3.0
error[E0034]: multiple applicable items in scope
   --> C:\Users\Steven Chm\.cargo\registry\src\github.com-1ecc6299db9ec823\tower-balance-0.3.0\src\pool\mod.rs:373:47
    |
373 |         if let Poll::Ready(()) = self.balance.poll_ready(cx)? {
    |                                               ^^^^^^^^^^ multiple `poll_ready` found
    |
note: candidate #1 is defined in an impl of the trait `tower_service::Service` for the type `p2c::service::Balance<_, _>`
   --> C:\Users\Steven Chm\.cargo\registry\src\github.com-1ecc6299db9ec823\tower-balance-0.3.0\src\p2c\service.rs:234:5
    |
234 |     fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = note: candidate #2 is defined in an impl of the trait `tower_make::make_service::MakeService` for the type `_`
help: disambiguate the method call for candidate #1
    |
373 |         if let Poll::Ready(()) = tower_service::Service::poll_ready(&mut self.balance, cx)? {
    |                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
help: disambiguate the method call for candidate #2
    |
373 |         if let Poll::Ready(()) = tower_make::make_service::MakeService::poll_ready(&mut self.balance, cx)? {
    |                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error[E0034]: multiple applicable items in scope
   --> C:\Users\Steven Chm\.cargo\registry\src\github.com-1ecc6299db9ec823\tower-balance-0.3.0\src\pool\mod.rs:418:37
    |
418 |                 return self.balance.poll_ready(cx);
    |                                     ^^^^^^^^^^ multiple `poll_ready` found
    |
note: candidate #1 is defined in an impl of the trait `tower_service::Service` for the type `p2c::service::Balance<_, _>`
   --> C:\Users\Steven Chm\.cargo\registry\src\github.com-1ecc6299db9ec823\tower-balance-0.3.0\src\p2c\service.rs:234:5
    |
234 |     fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = note: candidate #2 is defined in an impl of the trait `tower_make::make_service::MakeService` for the type `_`
help: disambiguate the method call for candidate #1
    |
418 |                 return tower_service::Service::poll_ready(&mut self.balance, cx);
    |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
help: disambiguate the method call for candidate #2
    |
418 |                 return tower_make::make_service::MakeService::poll_ready(&mut self.balance, cx);
    |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0034`.
error: could not compile `tower-balance`.

currently I fix it in local library, in case anyone who get same issue
tower-balance-0.3.0\src\pool\mod.rs:419:37

return tower_service::Service::poll_ready(&mut self.balance, cx);

tower-balance-0.3.0\src\pool\mod.rs:373:47

 if let Poll::Ready(()) = tower_service::Service::poll_ready(&mut self.balance, cx)? {

[LucioFranco]

@Stvchm9703 this seems like a regression with that nightly version, I would try again on an older/newer nightly and open an issue with rustc. In theory if it compiles on stable it should continue to compile unless there is an edition change.

[Stvchm9703]

thank you for fixing ;)