title: Is conda 4.9.2 reporting bogus package conflicts?
body: <p>Since bringing my <em>Anaconda</em> infrastructure up-to-date, including updating <code>conda</code> to v4.9.2, I'm finding that the installation of one of my packages: <code>pybert</code>, is broken.
  And, when I peruse the list of reported conflicts, I see things like this:</p>
  <pre><code>Package six conflicts for:
  chaco -&gt; enable[version='&gt;=4.8.0,&lt;4.9'] -&gt; six
  scikit-rf -&gt; six
  </code></pre>
  <p>which looks bogus to me.
  (Both paths lead to <code>six</code> with no version constraints; so, how can there be a conflict?)</p>
  <p>Am I misreading these conflict reports, or is <code>conda</code> broken again?</p>
  <p>Thanks!<br />
  -db</p>
  <p><strong>Dec. 13, 2020:</strong></p>
  <p>Responding to @merv (Thank you!), here is the complete output from my <code>conda install ...</code> command:</p>
  <pre><code>$ conda install -c dbanas -c conda-forge -c defaults --strict-channel-priority pybert
  Collecting package metadata (current_repodata.json): done
  Solving environment: failed with initial frozen solve. Retrying with flexible solve.
  Solving environment: failed with repodata from current_repodata.json, will retry with next repodata source.
  Collecting package metadata (repodata.json): done
  Solving environment: failed with initial frozen solve. Retrying with flexible solve.
  Solving environment: -
  Found conflicts! Looking for incompatible packages.
  This can take several minutes.  Press CTRL-C to abort.
  failed                                                                                                                                                         -
  
  UnsatisfiableError: The following specifications were found to be incompatible with each other:
  
  Output in format: Requested package -&gt; Available versions
  
  Package cython conflicts for:
  pyyaml -&gt; cython
  chaco -&gt; cython
  
  Package numpy conflicts for:
  pyibis-ami=3.3.3 -&gt; matplotlib -&gt; numpy[version='1.10.*|1.11.*|&gt;=1.14.6,&lt;2.0a0|&gt;=1.18.5,&lt;2.0a0|&gt;=1.16.5,&lt;2.0a0|&gt;=1.19.2,&lt;2.0a0|&gt;=1.18.1,&lt;2.0a0|&gt;=1.9.3,&lt;2.0a0|&gt;=1.11.3,&lt;2.0a0|&gt;=1.9|&gt;=1.11|1.13.*|1.12.*|&gt;=1.16.6,&lt;2.0a0|&gt;=1.15.1,&lt;2.0a0']
  scikit-rf -&gt; matplotlib-base -&gt; numpy[version='1.10.*|1.11.*|1.12.*|1.13.*|&gt;=1.11|&gt;=1.11.*|&gt;=1.11.3,&lt;2.0a0|&gt;=1.14.6,&lt;2.0a0|&gt;=1.15.4,&lt;2.0a0|&gt;=1.16.5,&lt;2.0a0|&gt;=1.18.5,&lt;2.0a0|&gt;=1.19.4,&lt;2.0a0|&gt;=1.19.2,&lt;2.0a0|&gt;=1.9.3,&lt;2.0a0|&gt;=1.16.6,&lt;2.0a0|&gt;=1.18.4,&lt;2.0a0|&gt;=1.18.1,&lt;2.0a0|&gt;=1.12.1,&lt;2.0a0|&gt;=1.9.*|&gt;=1.9|&gt;=1.8|&gt;=1.7|&gt;=1.13.3,&lt;2.0a0|&gt;=1.9.3,&lt;1.10.0a0|&gt;=1.15.1,&lt;2.0a0']
  chaco -&gt; enable[version='&gt;=4.8.0,&lt;4.9'] -&gt; numpy
  scikit-rf -&gt; numpy
  
  Package gdbm conflicts for:
  kiwisolver -&gt; pypy3.6[version='&gt;=7.3.2'] -&gt; gdbm[version='&gt;=1.18,&lt;1.19.0a0']
  python -&gt; pypy3.7=7.3.3 -&gt; gdbm[version='&gt;=1.18,&lt;1.19.0a0']
  pyyaml -&gt; pypy3.6[version='&gt;=7.3.2'] -&gt; gdbm[version='&gt;=1.18,&lt;1.19.0a0']
  
  Package setuptools conflicts for:
  chaco -&gt; cython -&gt; setuptools
  pyibis-ami=3.3.3 -&gt; matplotlib -&gt; setuptools
  pyyaml -&gt; cython -&gt; setuptools
  scikit-rf -&gt; ipython -&gt; setuptools[version='&gt;=18.5']
  python -&gt; pip -&gt; setuptools
  
  Package ca-certificates conflicts for:
  python -&gt; ca-certificates
  pyyaml -&gt; python[version='&gt;=2.7,&lt;2.8.0a0'] -&gt; ca-certificates
  pyside2 -&gt; python[version='&gt;=2.7,&lt;2.8.0a0'] -&gt; ca-certificates
  kiwisolver -&gt; python[version='&gt;=2.7,&lt;2.8.0a0'] -&gt; ca-certificates
  scikit-rf -&gt; python -&gt; ca-certificates
  
  Package matplotlib-base conflicts for:
  scikit-rf -&gt; matplotlib-base
  scikit-rf -&gt; matplotlib -&gt; matplotlib-base[version='2.1.2|2.1.2|2.1.2|2.2.3|2.2.3|2.2.3|2.2.4|2.2.4|2.2.4|2.2.4|2.2.4|2.2.4|2.2.4|2.2.4|2.2.4|2.2.4|3.0.1|3.0.2|3.0.2|3.0.2|3.0.2|3.0.2|3.0.3|3.0.3|3.0.3|3.0.3|3.1.0|3.1.0|3.1.0|3.1.0|3.1.1|3.1.1|3.1.1|3.1.1|3.1.1|3.1.1|3.1.1|3.1.1|3.1.2|3.1.2|3.1.2|3.1.2|3.1.2|3.1.2|3.1.3|3.1.3|3.1.3|&gt;=3.2.0,&lt;3.2.1.0a0|&gt;=3.2.1,&lt;3.2.2.0a0|&gt;=3.2.2,&lt;3.2.3.0a0|&gt;=3.3.0,&lt;3.3.1.0a0|&gt;=3.3.1,&lt;3.3.2.0a0|&gt;=3.3.2,&lt;3.3.3.0a0|&gt;=3.3.3,&lt;3.3.4.0a0|&gt;=2.2.5,&lt;2.2.6.0a0|3.1.3|3.1.3|3.1.3|3.1.2|3.1.2|3.1.2',build='py38h9aa3819_1|py36h9aa3819_0|py37h9aa3819_0|py36h31f9439_1|py37h31f9439_1|py36hd64abcd_1|py37h31f9439_1|py27h11da6c2_2|py36hf043ca5_1000|py36hf043ca5_1001|py37hf043ca5_1002|py36hf043ca5_0|py37hf043ca5_0|py36habd5b94_1|py37habd5b94_1|py37h3a684a6_1|py37h3a684a6_1|py36h11da6c2_2|py37h11da6c2_0|py38h11da6c2_0|py36h11da6c2_1|py37h11da6c2_1|py38h11da6c2_1|py37h11da6c2_0|py38h11da6c2_0|py36h11da6c2_0|py36h11da6c2_0|py38h11da6c2_2|py37h11da6c2_2|py38h11da6c2_1|py36h3a684a6_1|py36h3a684a6_0|py37h3a684a6_0|py36h3a684a6_1|py36habd5b94_0|py37habd5b94_0|py36hf043ca5_1002|py37hf043ca5_1001|py36hebca740_1001|py36h11da6c2_2|py38h11da6c2_2|py37h11da6c2_2|py36h31f9439_1|py27h31f9439_1|py27h3a684a6_0|py37h3a684a6_0|py36h3a684a6_0|py37hd64abcd_1|py27hd64abcd_1|py27h31f9439_1|py38h9aa3819_0|py36h9aa3819_1|py37h9aa3819_1']
  pyibis-ami=3.3.3 -&gt; matplotlib -&gt; matplotlib-base[version='2.1.2|2.1.2|2.1.2|2.2.3|2.2.3|2.2.3|2.2.4|2.2.4|2.2.4|2.2.4|2.2.4|2.2.4|2.2.4|2.2.4|2.2.4|2.2.4|3.0.1|3.0.2|3.0.2|3.0.2|3.0.2|3.0.2|3.0.3|3.0.3|3.0.3|3.0.3|3.1.0|3.1.0|3.1.0|3.1.0|3.1.1|3.1.1|3.1.1|3.1.1|3.1.1|3.1.1|3.1.1|3.1.1|3.1.2|3.1.2|3.1.2|3.1.2|3.1.2|3.1.2|3.1.3|3.1.3|3.1.3|&gt;=3.2.0,&lt;3.2.1.0a0|&gt;=3.2.1,&lt;3.2.2.0a0|&gt;=3.2.2,&lt;3.2.3.0a0|&gt;=3.3.0,&lt;3.3.1.0a0|&gt;=3.3.1,&lt;3.3.2.0a0|&gt;=3.3.2,&lt;3.3.3.0a0|&gt;=3.3.3,&lt;3.3.4.0a0|&gt;=2.2.5,&lt;2.2.6.0a0|3.1.3|3.1.3|3.1.3|3.1.2|3.1.2|3.1.2',build='py38h9aa3819_1|py36h9aa3819_0|py37h9aa3819_0|py36h31f9439_1|py37h31f9439_1|py36hd64abcd_1|py37h31f9439_1|py27h11da6c2_2|py36hf043ca5_1000|py36hf043ca5_1001|py37hf043ca5_1002|py36hf043ca5_0|py37hf043ca5_0|py36habd5b94_1|py37habd5b94_1|py37h3a684a6_1|py37h3a684a6_1|py36h11da6c2_2|py37h11da6c2_0|py38h11da6c2_0|py36h11da6c2_1|py37h11da6c2_1|py38h11da6c2_1|py37h11da6c2_0|py38h11da6c2_0|py36h11da6c2_0|py36h11da6c2_0|py38h11da6c2_2|py37h11da6c2_2|py38h11da6c2_1|py36h3a684a6_1|py36h3a684a6_0|py37h3a684a6_0|py36h3a684a6_1|py36habd5b94_0|py37habd5b94_0|py36hf043ca5_1002|py37hf043ca5_1001|py36hebca740_1001|py36h11da6c2_2|py38h11da6c2_2|py37h11da6c2_2|py36h31f9439_1|py27h31f9439_1|py27h3a684a6_0|py37h3a684a6_0|py36h3a684a6_0|py37hd64abcd_1|py27hd64abcd_1|py27h31f9439_1|py38h9aa3819_0|py36h9aa3819_1|py37h9aa3819_1']
  
  Package libpng conflicts for:
  pyside2 -&gt; qt[version='&gt;=5.12.9,&lt;5.13.0a0'] -&gt; libpng[version='&gt;=1.6.32,&lt;1.7.0a0|&gt;=1.6.34,&lt;1.7.0a0|&gt;=1.6.35,&lt;1.7.0a0|&gt;=1.6.37,&lt;1.7.0a0']
  scikit-rf -&gt; matplotlib-base -&gt; libpng[version='&gt;=1.6.23,&lt;1.7|&gt;=1.6.35,&lt;1.7.0a0|&gt;=1.6.37,&lt;1.7.0a0|&gt;=1.6.36,&lt;1.7.0a0|&gt;=1.6.34,&lt;1.7.0a0|&gt;=1.6.32,&lt;1.7.0a0']
  pyibis-ami=3.3.3 -&gt; matplotlib -&gt; libpng[version='&gt;=1.6.23,&lt;1.7|&gt;=1.6.37,&lt;1.7.0a0|&gt;=1.6.36,&lt;1.7.0a0|&gt;=1.6.35,&lt;1.7.0a0|&gt;=1.6.34,&lt;1.7.0a0|&gt;=1.6.32,&lt;1.7.0a0']
  
  Package libcxxabi conflicts for:
  pyside2 -&gt; libcxx[version='&gt;=4.0.1'] -&gt; libcxxabi[version='4.0.1|4.0.1|8.0.0|8.0.0|8.0.0|8.0.0|8.0.1',build='hcfea43d_1|1|2|0|4|3|hebd6815_0']
  python -&gt; libcxx[version='&gt;=4.0.1'] -&gt; libcxxabi[version='4.0.1|4.0.1|8.0.0|8.0.0|8.0.0|8.0.0|8.0.1',build='hcfea43d_1|1|2|0|4|3|hebd6815_0']
  kiwisolver -&gt; libcxx[version='&gt;=4.0.1'] -&gt; libcxxabi[version='4.0.1|4.0.1|8.0.0|8.0.0|8.0.0|8.0.0|8.0.1',build='hcfea43d_1|1|2|0|4|3|hebd6815_0']
  
  Package six conflicts for:
  chaco -&gt; enable[version='&gt;=4.8.0,&lt;4.9'] -&gt; six
  scikit-rf -&gt; six
  
  Package kiwisolver conflicts for:
  scikit-rf -&gt; matplotlib-base -&gt; kiwisolver[version='&gt;=1.0.1']
  kiwisolver
  Note that strict channel priority may have removed packages required for satisfiability.
  </code></pre>
  <p>And here are versions for each &quot;conflicting&quot; package mentioned in that output, which I believe meet all dependents' requirements:</p>
  <div class="s-table-container">
  <table class="s-table">
  <thead>
  <tr>
  <th style="text-align: left;">Package</th>
  <th style="text-align: right;">Version</th>
  <th style="text-align: right;">Build</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td style="text-align: left;">cython</td>
  <td style="text-align: right;">(any)</td>
  <td style="text-align: right;">(any)</td>
  </tr>
  <tr>
  <td style="text-align: left;">numpy</td>
  <td style="text-align: right;">1.19.2</td>
  <td style="text-align: right;">(any)</td>
  </tr>
  <tr>
  <td style="text-align: left;">gdbm</td>
  <td style="text-align: right;">1.18</td>
  <td style="text-align: right;">(any)</td>
  </tr>
  <tr>
  <td style="text-align: left;">setuptools</td>
  <td style="text-align: right;">18.5</td>
  <td style="text-align: right;">(any)</td>
  </tr>
  <tr>
  <td style="text-align: left;">ca-certificates</td>
  <td style="text-align: right;">(any)</td>
  <td style="text-align: right;">(any)</td>
  </tr>
  <tr>
  <td style="text-align: left;">matplotlib-base</td>
  <td style="text-align: right;">2.1.2</td>
  <td style="text-align: right;">(any)</td>
  </tr>
  <tr>
  <td style="text-align: left;">libpng</td>
  <td style="text-align: right;">1.6.35</td>
  <td style="text-align: right;">(any)</td>
  </tr>
  <tr>
  <td style="text-align: left;">libcxxabi</td>
  <td style="text-align: right;">4.0.1</td>
  <td style="text-align: right;">hcfea43d_1</td>
  </tr>
  <tr>
  <td style="text-align: left;">six</td>
  <td style="text-align: right;">(any)</td>
  <td style="text-align: right;">(any)</td>
  </tr>
  <tr>
  <td style="text-align: left;">kiwisolver</td>
  <td style="text-align: right;">1.0.1</td>
  <td style="text-align: right;">(any)</td>
  </tr>
  </tbody>
  </table>
  </div>
  <p>I'm very curious: does anyone reading this disagree with any of my claimed working versions, above?
  (I'm still wondering if I don't quite understand how to interpret this output.)</p>
  <p>Judging from my own experience, here, and from what I've found while searching on this topic, it seems likely that <code>conda</code> is currently broken, in this regard (i.e. - identifying true conflicts).
  Who are the right folks to talk to about lending a hand in getting this fixed?</p>
  <p>Thanks!<br />
  -db</p>