py_zipkin broken under Python 3.7

[stuhood]

py_zipkin transitively uses thriftpy, which does not work under Python 3.7. The native code that it uses fails to compile with: https://gist.github.com/stuhood/badaf3196d6fdfcd4b4ff8113f9e8931

Upstream, the maintainers indicate that thriftpy is deprecated in favor of thriftpy2: Thriftpy/thriftpy#333

[illicitonion]

Upstream has a patch to fix this, which I've verified can install in python3.7 with:

$ git diff
diff --git 3rdparty/python/requirements.txt 3rdparty/python/requirements.txt
index 1ac736f..6db6a30 100644
--- 3rdparty/python/requirements.txt
+++ 3rdparty/python/requirements.txt
@@ -27,6 +27,7 @@ pystache==0.5.3
 pytest-cov>=2.5,<2.6
 pytest>=3.4,<4.0
 pywatchman==1.4.1
+-e git://github.com/drolando/py_zipkin.git@1bc1adda7887604d6b41fadca24660ac0266435f#egg=py_zipkin
 requests[security]>=2.20.1
 responses==0.10.4
 scandir==1.2
@@ -37,4 +38,3 @@ subprocess32==3.2.7 ; python_version<'3'
 thrift>=0.10.0
 wheel==0.31.1
 www-authenticate==0.9.2
-py_zipkin==0.16.1

Unfortunately pants's python_requirements rule doesn't understand this requirements.txt format, so I can't push this; asked upstream what the ETA on the fix being released is.

[drolando]

py-zipkin>=0.17.0 should work fine on python3.7

[stuhood]

Fixed in #7161