Fix compiletest upstream bug (osx nightly builds)

This is a temporary fix, see Manishearth/compiletest-rs#155

hdf5-derive/tests/compile-test.rs

@@ -1,3 +1,4 @@
+use std::env;
 use std::fs::{read_dir, remove_file};
 
 // Workaround for https://github.com/laumann/compiletest-rs/issues/114
@@ -26,6 +27,20 @@ fn clean_rlibs(config: &compiletest_rs::Config) {
     }
 }
 
+fn link_deps(config: &mut compiletest_rs::Config) {
+    // https://github.com/laumann/compiletest-rs/issues/155
+    if cfg!(target_os = "macos") {
+        if let Ok(lib_paths) = env::var("DYLD_FALLBACK_LIBRARY_PATH") {
+            let mut flags = config.target_rustcflags.take().unwrap_or_else(String::new);
+            for p in env::split_paths(&lib_paths) {
+                flags += " -L ";
+                flags += p.to_str().unwrap(); // Can't fail. We already know this is unicode
+            }
+            config.target_rustcflags = Some(flags);
+        }
+    }
+}
+
 fn run_mode(mode: &'static str) {
     let mut config = compiletest_rs::Config::default();
     let cfg_mode = mode.parse().expect("Invalid mode");
@@ -34,6 +49,7 @@ fn run_mode(mode: &'static str) {
     config.src_base = format!("tests/{}", mode).into();
     config.verbose = false;
     config.link_deps();
+    link_deps(&mut config);
     // clean_rlibs(&config);  // commented out for now as it's flaky on CI
 
     compiletest_rs::run_tests(&config);