Build backwards-compatible Mac executables on flatiron mac

[serban-nicusor-toptal]

Submission Checklist

• [ ] Run unit tests
• Documentation
  • [ ] If a user-facing facing change was made, the documentation PR is here:
  • [x] OR, no user-facing changes were made

Release notes

CI change, build backwards-compatible Mac executables on flatiron mac.

Copyright and Licensing

By submitting this pull request, the copyright holder is agreeing to license the submitted work under the BSD 3-clause license (https://opensource.org/licenses/BSD-3-Clause)

[WardBrian]

@serban-nicusor-toptal did you confirm the built binaries from this run on the old gelman-mac?

[serban-nicusor-toptal]

Hey @WardBrian I think it's ready for review. I ran a test job here: https://jenkins.flatironinstitute.org/blue/organizations/jenkins/Stan%2FStanc3/detail/PR-1255/2/artifacts Where you can find the binary, I ran it on the gelman mac ( --help ) and it seems to work fine.

[serban-nicusor-toptal]

I will give it another try on the old-imac instance. ( also --help )

d1m1s1b1:tmp XXX$ ./mac-stanc --version
stanc3 v2.30.0-66-g8fe98f94 (Unix)
d1m1s1b1:tmp XXX$ sw_vers
ProductName:    Mac OS X
ProductVersion: 10.13.4
BuildVersion:   17E199

gelman-group-mac:tmp XXX$ ./mac-stanc --version
stanc3 v2.30.0-66-g8fe98f94 (Unix)
gelman-group-mac:tmp XXX$ sw_vers
ProductName:    Mac OS X
ProductVersion: 10.11.6
BuildVersion:   15G22010

[WardBrian]

Awesome, thanks!

[serban-nicusor-toptal]

Thank you too for the work on this! Will merge the PR now.