spyder: Can't install spyder 4.2.1 using the conda install spyder=4.2.1 command in mac terminal

Issue Report Checklist

• Searched the issues page for similar reports
• Read the relevant sections of the Spyder Troubleshooting Guide and followed its advice
• Reproduced the issue after updating with conda update spyder (or pip, if not using Anaconda)
• Could not reproduce inside jupyter qtconsole (if console-related)
• Tried basic troubleshooting (if a bug/error)
  • Restarted Spyder
  • Reset preferences with spyder --reset
  • Reinstalled the latest version of Anaconda
  • Tried the other applicable steps from the Troubleshooting Guide
• Completed the Problem Description, Steps to Reproduce and Version sections below

Problem Description

Can’t install spyder 4.2.1 using the conda install spyder=4.2.1 command. I get the following error:

PackagesNotFoundError: The following packages are not available from current channels:

• spyder=4.2.1

What steps reproduce the problem?

1. conda install spyder=4.2.1

What is the expected output? What do you see instead?

Paste Traceback/Error Below (if applicable)

PackagesNotFoundError: The following packages are not available from current channels:

  - spyder=4.2.1
 

Versions

• Spyder version: 4.2.0
• Python version: 3.8.5
• Qt version:
• PyQt version:
• Operating System name/version: macos 11.1

Dependencies

# Mandatory:
applaunchservices >=0.1.7      :  0.2.1 (OK)
atomicwrites >=1.2.0           :  1.4.0 (OK)
chardet >=2.0.0                :  3.0.4 (OK)
cloudpickle >=0.5.0            :  1.6.0 (OK)
diff_match_patch >=20181111    :  20200713 (OK)
intervaltree                   :  None (OK)
IPython >=4.0                  :  7.19.0 (OK)
jedi =0.17.1                   :  0.17.1 (OK)
nbconvert >=4.0                :  6.0.7 (OK)
numpydoc >=0.6.0               :  1.1.0 (OK)
parso =0.7.0                   :  0.7.0 (OK)
pexpect >=4.4.0                :  4.8.0 (OK)
pickleshare >=0.4              :  0.7.5 (OK)
psutil >=5.3                   :  5.7.2 (OK)
pygments >=2.0                 :  2.7.2 (OK)
pylint >=1.0                   :  2.6.0 (OK)
pyls >=0.34.0;<1.0.0           :  0.35.1 (OK)
qdarkstyle >=2.8               :  2.8.1 (OK)
qtawesome >=0.5.7              :  1.0.1 (OK)
qtconsole >=4.6.0              :  4.7.7 (OK)
qtpy >=1.5.0                   :  1.9.0 (OK)
rtree >=0.8.3                  :  0.9.4 (OK)
sphinx >=0.6.6                 :  3.2.1 (OK)
spyder_kernels >=1.9.4;<1.10.0 :  1.9.4 (OK)
watchdog                       :  None (OK)
zmq >=17                       :  20.0.0 (OK)

# Optional:
cython >=0.21                  :  None (OK)
matplotlib >=2.0.0             :  3.3.2 (OK)
numpy >=1.7                    :  1.19.2 (OK)
pandas >=0.13.1                :  1.1.3 (OK)
scipy >=0.17.0                 :  None (OK)
sympy >=0.7.3                  :  None (OK)