Updating or removing Python version pinning

[emiliom]

• [X ] I read the conda-forge documentation and could not find the solution for my problem there.

Issue:
The ulmo conda-forge package apparently does not work with Python 3.7 or 3.8. It seems to be pinned to 3.6 (I haven't checked against lower versions). This restriction is not present in the ulmo PyPI package. See ulmo-dev/ulmo#200

I don't know where it's set, but my bet guess is https://github.com/conda-forge/ulmo-feedstock/blob/master/.ci_support/linux_64_.yaml#L12
Is that something I can change myself via a PR? If so, what should it be changed to? An explicit list of supported versions, or only the most recent supported version? eg:

python:
- 3.5.* *_cpython 3.6.* *_cpython 3.7.* *_cpython 3.8.* *_cpython

or

python:
- 3.8.* *_cpython

Note: the conda details presented below are for one of my tests, using a fairly minimal conda env. But others have confirmed this issue with similar tests in their own environments and platforms.

Environment (conda list):

$ conda list
# packages in environment at /home/mayorga/miniconda/envs/ulmotest:
#
# Name                    Version                   Build  Channel
_libgcc_mutex             0.1                 conda_forge    conda-forge
_openmp_mutex             4.5                       1_gnu    conda-forge
appdirs                   1.4.4              pyh9f0ad1d_0    conda-forge
attrs                     20.3.0             pyhd3deb0d_0    conda-forge
backports                 1.0                        py_2    conda-forge
backports.functools_lru_cache 1.6.1                      py_0    conda-forge
beautifulsoup4            4.9.3              pyhb0f4dca_0    conda-forge
blosc                     1.21.0               h9c3ff4c_0    conda-forge
branca                    0.4.2              pyhd8ed1ab_0    conda-forge
brotlipy                  0.7.0           py36h8f6f2f9_1001    conda-forge
bzip2                     1.0.8                h7f98852_4    conda-forge
c-ares                    1.17.1               h7f98852_1    conda-forge
ca-certificates           2020.12.5            ha878542_0    conda-forge
certifi                   2020.12.5        py36h5fab9bb_1    conda-forge
cffi                      1.14.5           py36hc120d54_0    conda-forge
chardet                   4.0.0            py36h5fab9bb_1    conda-forge
cryptography              3.4.6            py36hb60f036_0    conda-forge
cycler                    0.10.0                     py_2    conda-forge
dbus                      1.13.6               hfdff14a_1    conda-forge
decorator                 4.4.2                      py_0    conda-forge
expat                     2.2.10               h9c3ff4c_0    conda-forge
folium                    0.12.0             pyhd8ed1ab_1    conda-forge
fontconfig                2.13.1            hba837de_1004    conda-forge
freetype                  2.10.4               h0708190_1    conda-forge
freezegun                 1.1.0              pyhd8ed1ab_0    conda-forge
future                    0.18.2           py36h5fab9bb_3    conda-forge
geojson                   2.5.0                      py_0    conda-forge
gettext                   0.19.8.1          h0b5b191_1005    conda-forge
glib                      2.66.7               h9c3ff4c_1    conda-forge
glib-tools                2.66.7               h9c3ff4c_1    conda-forge
gst-plugins-base          1.18.4               h29181c9_0    conda-forge
gstreamer                 1.18.4               h76c114f_0    conda-forge
hdf5                      1.10.6          nompi_h6a2412b_1114    conda-forge
html5lib                  0.9999999                py36_0    conda-forge
icu                       68.1                 h58526e2_0    conda-forge
idna                      2.10               pyh9f0ad1d_0    conda-forge
importlib-metadata        3.7.3            py36h5fab9bb_0    conda-forge
importlib_metadata        3.7.3                hd8ed1ab_0    conda-forge
iniconfig                 1.1.1              pyh9f0ad1d_0    conda-forge
ipykernel                 5.5.0            py36he448a4c_1    conda-forge
ipython                   5.8.0                    py36_1    conda-forge
ipython_genutils          0.2.0                      py_1    conda-forge
isodate                   0.6.0                      py_1    conda-forge
jinja2                    2.11.3             pyh44b312d_0    conda-forge
jpeg                      9d                   h36c2ea0_0    conda-forge
jupyter_client            6.1.12             pyhd8ed1ab_0    conda-forge
jupyter_core              4.7.1            py36h5fab9bb_0    conda-forge
kiwisolver                1.3.1            py36h605e78d_1    conda-forge
krb5                      1.17.2               h926e7f8_0    conda-forge
lcms2                     2.12                 hddcbb42_0    conda-forge
ld_impl_linux-64          2.35.1               hea4e1c9_2    conda-forge
libblas                   3.9.0                8_openblas    conda-forge
libcblas                  3.9.0                8_openblas    conda-forge
libclang                  11.1.0          default_ha53f305_0    conda-forge
libcurl                   7.75.0               hc4aaa36_0    conda-forge
libedit                   3.1.20191231         he28a2e2_2    conda-forge
libev                     4.33                 h516909a_1    conda-forge
libevent                  2.1.10               hcdb4288_3    conda-forge
libffi                    3.3                  h58526e2_2    conda-forge
libgcc-ng                 9.3.0               h2828fa1_18    conda-forge
libgfortran-ng            9.3.0               hff62375_18    conda-forge
libgfortran5              9.3.0               hff62375_18    conda-forge
libglib                   2.66.7               h3e27bee_1    conda-forge
libgomp                   9.3.0               h2828fa1_18    conda-forge
libiconv                  1.16                 h516909a_0    conda-forge
liblapack                 3.9.0                8_openblas    conda-forge
libllvm11                 11.1.0               hf817b99_0    conda-forge
libnghttp2                1.43.0               h812cca2_0    conda-forge
libopenblas               0.3.12          pthreads_h4812303_1    conda-forge
libpng                    1.6.37               h21135ba_2    conda-forge
libpq                     13.1                 hfd2b0eb_2    conda-forge
libsodium                 1.0.18               h36c2ea0_1    conda-forge
libssh2                   1.9.0                ha56f1ee_6    conda-forge
libstdcxx-ng              9.3.0               h6de172a_18    conda-forge
libtiff                   4.2.0                hdc55705_0    conda-forge
libuuid                   2.32.1            h7f98852_1000    conda-forge
libwebp-base              1.2.0                h7f98852_2    conda-forge
libxcb                    1.13              h7f98852_1003    conda-forge
libxkbcommon              1.0.3                he3ba5ed_0    conda-forge
libxml2                   2.9.10               h72842e0_3    conda-forge
libxslt                   1.1.33               h15afd5d_2    conda-forge
lxml                      4.6.2            py36h04a5ba7_1    conda-forge
lz4-c                     1.9.3                h9c3ff4c_0    conda-forge
lzo                       2.10              h516909a_1000    conda-forge
markupsafe                1.1.1            py36h8f6f2f9_3    conda-forge
matplotlib                3.3.4            py36h5fab9bb_0    conda-forge
matplotlib-base           3.3.4            py36hd391965_0    conda-forge
mock                      4.0.3            py36h5fab9bb_1    conda-forge
more-itertools            8.7.0              pyhd8ed1ab_0    conda-forge
mysql-common              8.0.23               ha770c72_1    conda-forge
mysql-libs                8.0.23               h935591d_1    conda-forge
ncurses                   6.2                  h58526e2_4    conda-forge
nspr                      4.30                 h9c3ff4c_0    conda-forge
nss                       3.62                 hb5efdd6_0    conda-forge
numexpr                   2.7.3            py36h284efc9_0    conda-forge
numpy                     1.19.5           py36h2aa4a07_1    conda-forge
olefile                   0.46               pyh9f0ad1d_1    conda-forge
openssl                   1.1.1j               h7f98852_0    conda-forge
packaging                 20.9               pyh44b312d_0    conda-forge
pandas                    1.1.5            py36h284efc9_0    conda-forge
pcre                      8.44                 he1b5a44_0    conda-forge
pexpect                   4.8.0              pyh9f0ad1d_2    conda-forge
pickleshare               0.7.5                   py_1003    conda-forge
pillow                    8.1.2            py36ha6010c0_0    conda-forge
pip                       21.0.1             pyhd8ed1ab_0    conda-forge
pluggy                    0.13.1           py36h5fab9bb_4    conda-forge
prompt_toolkit            1.0.15                     py_1    conda-forge
pthread-stubs             0.4               h36c2ea0_1001    conda-forge
ptyprocess                0.7.0              pyhd3deb0d_0    conda-forge
py                        1.10.0             pyhd3deb0d_0    conda-forge
pycparser                 2.20               pyh9f0ad1d_2    conda-forge
pygments                  2.8.1              pyhd8ed1ab_0    conda-forge
pyopenssl                 20.0.1             pyhd8ed1ab_0    conda-forge
pyparsing                 2.4.7              pyh9f0ad1d_0    conda-forge
pyqt                      5.12.3           py36h5fab9bb_7    conda-forge
pyqt-impl                 5.12.3           py36h7ec31b9_7    conda-forge
pyqt5-sip                 4.19.18          py36hc4f0c31_7    conda-forge
pyqtchart                 5.12             py36h7ec31b9_7    conda-forge
pyqtwebengine             5.12.1           py36h7ec31b9_7    conda-forge
pysocks                   1.7.1            py36h5fab9bb_3    conda-forge
pytables                  3.6.1            py36hb7ec5aa_3    conda-forge
pytest                    6.2.2            py36h5fab9bb_0    conda-forge
python                    3.6.13          hffdb5ce_0_cpython    conda-forge
python-dateutil           2.8.1                      py_0    conda-forge
python_abi                3.6                     1_cp36m    conda-forge
pytz                      2021.1             pyhd8ed1ab_0    conda-forge
pyzmq                     22.0.3           py36h7068817_1    conda-forge
qt                        5.12.9               hda022c4_4    conda-forge
readline                  8.0                  he28a2e2_2    conda-forge
requests                  2.25.1             pyhd3deb0d_0    conda-forge
setuptools                49.6.0           py36h5fab9bb_3    conda-forge
simplegeneric             0.8.1                      py_1    conda-forge
six                       1.15.0             pyh9f0ad1d_0    conda-forge
soupsieve                 2.0.1                      py_1    conda-forge
sqlite                    3.34.0               h74cdb3f_0    conda-forge
suds-jurko                0.6             py36h5fab9bb_1005    conda-forge
tk                        8.6.10               h21135ba_1    conda-forge
toml                      0.10.2             pyhd8ed1ab_0    conda-forge
tornado                   6.1              py36h8f6f2f9_1    conda-forge
traitlets                 4.3.3            py36h9f0ad1d_1    conda-forge
typing_extensions         3.7.4.3                    py_0    conda-forge
ulmo                      0.8.6              pyh9f0ad1d_0    conda-forge
urllib3                   1.26.4             pyhd8ed1ab_0    conda-forge
wcwidth                   0.2.5              pyh9f0ad1d_2    conda-forge
webencodings              0.5.1                      py_1    conda-forge
wheel                     0.36.2             pyhd3deb0d_0    conda-forge
xorg-libxau               1.0.9                h7f98852_0    conda-forge
xorg-libxdmcp             1.1.3                h7f98852_0    conda-forge
xz                        5.2.5                h516909a_1    conda-forge
zeromq                    4.3.4                h9c3ff4c_0    conda-forge
zipp                      3.4.1              pyhd8ed1ab_0    conda-forge
zlib                      1.2.11            h516909a_1010    conda-forge
zstd                      1.4.9                ha95c52a_0    conda-forge

Details about conda and system ( conda info ):

$ conda info

     active environment : ulmotest
    active env location : /home/mayorga/miniconda/envs/ulmotest
            shell level : 1
       user config file : /home/mayorga/.condarc
 populated config files : /home/mayorga/.condarc
          conda version : 4.9.2
    conda-build version : not installed
         python version : 3.7.3.final.0
       virtual packages : __glibc=2.27=0
                          __unix=0=0
                          __archspec=1=x86_64
       base environment : /home/mayorga/miniconda  (writable)
           channel URLs : https://conda.anaconda.org/conda-forge/linux-64
                          https://conda.anaconda.org/conda-forge/noarch
                          https://repo.anaconda.com/pkgs/main/linux-64
                          https://repo.anaconda.com/pkgs/main/noarch
                          https://repo.anaconda.com/pkgs/r/linux-64
                          https://repo.anaconda.com/pkgs/r/noarch
          package cache : /home/mayorga/miniconda/pkgs
                          /home/mayorga/.conda/pkgs
       envs directories : /home/mayorga/miniconda/envs
                          /home/mayorga/.conda/envs
               platform : linux-64
             user-agent : conda/4.9.2 requests/2.25.0 CPython/3.7.3 Linux/5.3.0-7648-generic ubuntu/18.04.5 glibc/2.27
                UID:GID : 1000:1000
             netrc file : /home/mayorga/.netrc
           offline mode : False