Mayavi 4.7.1 doesn't work on python 3.7.9 from conda-forge

When I try to run `from myavi import mlab` the shell just shutdowns with no error.

The env was built from scratch using python 3.7

`conda create --name last_chance python=3.7`
`conda install -c conda-forge mayavi=4.7.1`

> added / updated specs:
> - mayavi=4.7.1
>
>
> The following NEW packages will be INSTALLED:
>
> apptools conda-forge/noarch::apptools-4.5.0-pyh9f0ad1d_1
> bzip2 conda-forge/win-64::bzip2-1.0.8-h8ffe710_4
> configobj conda-forge/noarch::configobj-5.0.6-py_0
> curl pkgs/main/win-64::curl-7.71.1-h2a8f88b_1
> envisage conda-forge/noarch::envisage-4.9.2-pyh9f0ad1d_1
> expat pkgs/main/win-64::expat-2.2.10-h33f27b4_2
> freetype conda-forge/win-64::freetype-2.10.4-h546665d_0
> future conda-forge/win-64::future-0.18.2-py37h03978a9_2
> hdf4 conda-forge/win-64::hdf4-4.2.13-h0e5069d_1004
> hdf5 conda-forge/win-64::hdf5-1.10.6-nompi_h5268f04_1112
> icc_rt pkgs/main/win-64::icc_rt-2019.0.0-h0cc432a_1
> icu conda-forge/win-64::icu-67.1-h33f27b4_0
> intel-openmp conda-forge/win-64::intel-openmp-2020.3-h57928b3_311
> jpeg conda-forge/win-64::jpeg-9d-h8ffe710_0
> jsoncpp conda-forge/win-64::jsoncpp-1.8.4-h1ad3211_1002
> krb5 pkgs/main/win-64::krb5-1.18.2-hc04afaa_0
> libblas conda-forge/win-64::libblas-3.8.0-21_mkl
> libcblas conda-forge/win-64::libcblas-3.8.0-21_mkl
> libclang conda-forge/win-64::libclang-10.0.1-default_hf44288c_1
> libcurl pkgs/main/win-64::libcurl-7.71.1-h2a8f88b_1
> libiconv conda-forge/win-64::libiconv-1.16-he774522_0
> liblapack conda-forge/win-64::liblapack-3.8.0-21_mkl
> libnetcdf conda-forge/win-64::libnetcdf-4.7.4-nompi_h3a9aa94_107
> libpng conda-forge/win-64::libpng-1.6.37-h1d00b33_2
> libssh2 conda-forge/win-64::libssh2-1.9.0-hb06d900_5
> libtiff conda-forge/win-64::libtiff-4.1.0-hc10be44_6
> libxml2 conda-forge/win-64::libxml2-2.9.10-h1006b36_2
> lz4-c conda-forge/win-64::lz4-c-1.9.2-h62dcd97_2
> mayavi pkgs/main/win-64::mayavi-4.7.1-py37h11817fe_2
> mkl conda-forge/win-64::mkl-2020.4-hb70f87d_311
> numpy conda-forge/win-64::numpy-1.19.4-py37hd20adf4_1
> pyface conda-forge/noarch::pyface-7.1.0-pyh9f0ad1d_0
> pygments conda-forge/noarch::pygments-2.7.3-pyhd8ed1ab_0
> pyqt conda-forge/win-64::pyqt-5.12.3-py37h03978a9_6
> pyqt-impl conda-forge/win-64::pyqt-impl-5.12.3-py37hf2a7229_6
> pyqt5-sip conda-forge/win-64::pyqt5-sip-4.19.18-py37hf2a7229_6
> pyqtchart conda-forge/win-64::pyqtchart-5.12-py37hf2a7229_6
> pyqtwebengine conda-forge/win-64::pyqtwebengine-5.12.1-py37hf2a7229_6
> qt conda-forge/win-64::qt-5.12.9-hb2cf2c5_0
> six conda-forge/noarch::six-1.15.0-pyh9f0ad1d_0
> tbb pkgs/main/win-64::tbb-2020.3-h74a9793_0
> tk conda-forge/win-64::tk-8.6.10-h8ffe710_1
> traits conda-forge/win-64::traits-6.1.1-py37hcc03f2d_0
> traitsui conda-forge/noarch::traitsui-7.1.0-pyh9f0ad1d_0
> vtk conda-forge/win-64::vtk-8.2.0-py37h359a0f6_218
> xz conda-forge/win-64::xz-5.2.5-h62dcd97_1
> zlib conda-forge/win-64::zlib-1.2.11-h62dcd97_1010
> zstd conda-forge/win-64::zstd-1.4.5-h1f3a1b7_2
>
>
> Proceed ([y]/n)? y
>
> Preparing transaction: done
> Verifying transaction: done
> Executing transaction: done