Build fails on OS X < 10.11

[causal-agent]

yup-oauth2 fails to build on Travis CI OS X workers:

   Compiling yup-oauth2 v0.5.4
     Running `/Users/travis/build/programble/fresh/target/debug/build/yup-oauth2-6fcf5dac526993e1/build-script-build`
Build failed, waiting for other jobs to finish...
failed to run custom build command for `yup-oauth2 v0.5.4`
Process didn't exit successfully: `/Users/travis/build/programble/fresh/target/debug/build/yup-oauth2-6fcf5dac526993e1/build-script-build` (signal: 11)
--- stderr
thread '<main>' has overflowed its stack

https://travis-ci.org/programble/fresh/jobs/107171816

This seems to be the only place this happens. Building locally on OS X works fine.

[Byron]

Thanks for letting me know ! I have opened an issue in the project that I suspect is causing this issue.
In the meanwhile, I will leave this one open until there is a solution.

[causal-agent]

Getting this issue on a different OS X machine running Yosemite 10.10. Seems like it breaks on OS X < 10.11, since Travis runs OS X 10.9.5.

[causal-agent]

It seems that this is definitely a distinct issue from Byron/google-apis-rs#148, since there doesn't appear to be any older version of serde_codegen + syntex that doesn't overflow.