link_deps() should also parse DYLD_FALLBACK_LIBRARY_PATH on OS X

[aldanor]

This seems to have something to do with nightly, not sure exactly what. Also, it only happens on OS X (I'm running the same tests on travis/appveyor on linux/osx/win).

I've tried adding some logging before/after calling config.link_deps(), here's the results (formatted for readability):

stable:

BEFORE: None

AFTER: Some("
    -L ~/dev/rust/hdf5-rs/target/debug/deps 
    -L ~/dev/rust/hdf5-rs/target/debug 
    -L ~/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/x86_64-apple-darwin/lib 
    -L ~/.rustup/toolchains/stable-x86_64-apple-darwin/lib
")

nightly:

BEFORE: None

AFTER: Some(" -L ~/.rustup/toolchains/nightly-x86_64-apple-darwin/lib")

I'm a bit lost; any thoughts? (will try to keep digging to see if there's anything else I can find out)

[aldanor]

This seems to be related to DYLD_LIBRARY_PATH which .link_deps() tries to parse; logging it yields:

// stable
DYLD_LIBRARY_PATH = "
    ~/dev/rust/hdf5-rs/target/debug/deps
    :~/dev/rust/hdf5-rs/target/debug
    :~/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/x86_64-apple-darwin/lib
    :~/.rustup/toolchains/stable-x86_64-apple-darwin/lib
"

// nightly
DYLD_LIBRARY_PATH = "~/.rustup/toolchains/nightly-x86_64-apple-darwin/lib" // ???

[aldanor]

However, now there's this, which seems to have all of the missing paths: (???)

DYLD_FALLBACK_LIBRARY_PATH = "
    ~/dev/rust/hdf5-rs/target/debug/deps
    :~/dev/rust/hdf5-rs/target/debug
    :~/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/x86_64-apple-darwin/lib
"

[aldanor]

https://github.com/rust-lang/cargo/pull/6355/commits/b7516d386377dc2de5fd892a5f97bb62cf71888a

[laumann]

@aldanor Thanks for tracking this. Can we just make the change to link_deps() directly and use DYLD_FALLBACK_LIBRARY_PATH instead of DYLD_LIBRARY_PATH? Or are there some caveats?