warning: redundant linker flag

[Boscop]

On Win 8.1, using a build script override for portaudio, I get this warning:

     Running `rustc --crate-name portaudio_sys rust-portaudio-sys\src\lib.rs --c
rate-type rlib --emit=dep-info,link -C debuginfo=2 -C metadata=3b728bd95cd452ea
-C extra-filename=-3b728bd95cd452ea --out-dir D:\projects\forks\rust-portaudio\t
arget\debug\deps -L dependency=D:\projects\forks\rust-portaudio\target\debug\dep
s -L D:\3rdparty\_rustlibs\64bit -l portaudio`
warning: redundant linker flag specified for library `portaudio`

[LinusU]

Getting this on macOS as well 🤔

[austin-millan]

Getting a similar warning on macOS:

warning: redundant linker flag specified for library `portaudio`

I thought maybe this was due to having a local portaudio installed while still specifying a portaudio crate in my Cargo.toml file, but when I uninstalled the other portaudio using Homebrew I'm still getting the same warning on each clean build using rustc.