Try just giving matplotlib <3 in run reqs
@@ -29,7 +29,7 @@ requirements:
- {{ pin_compatible('eigen') }}
- {{ pin_compatible('fftw') }}
- {{ pin_compatible('gpi') }}
- - matplotlib >=2.1,<3
+ - matplotlib <3
# - matplotlib <2 # [linux]
- {{ pin_compatible('numpy') }}
- {{ pin_compatible('python') }}
