Maybe just declaring one compiler helps.  Also, drop Python 2.7.
@@ -12,10 +12,10 @@ source:
build:
number: 0
script: "{{ PYTHON }} -m pip install . -vv"
+ skip: True # [py<35]
requirements:
build:
- - {{ compiler('c') }}
- {{ compiler('cxx') }}
host:
- cython
