<h4 dir="auto">Describe the bug</h4>
<p dir="auto">Running existing packages/programs with the latest release of 0.23.0 gives an import error on <code class="notranslate">MaskedArray</code>.</p>
<p dir="auto">Bounding the requirements to <code class="notranslate">&lt; 0.23.0</code> resolves this issue, but then it reverts to the older version although would be good to be on the latest release.</p>
<h4 dir="auto">Steps/Code to Reproduce</h4>
<p dir="auto"><em>Setup</em></p>
<div class="highlight highlight-source-shell notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="$ pip install scikit-learn&gt;=0.20.2

or 

$ pip install scikit-learn==0.23.0"><pre class="notranslate">$ pip install scikit-learn<span class="pl-k">&gt;</span>=0.20.2

or 

$ pip install scikit-learn==0.23.0</pre></div>
<p dir="auto"><em>Code</em></p>
<div class="highlight highlight-source-python notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="from sklearn.utils.fixes import MaskedArray
....
&lt;rest of your code&gt;"><pre class="notranslate"><span class="pl-k">from</span> <span class="pl-s1">sklearn</span>.<span class="pl-s1">utils</span>.<span class="pl-s1">fixes</span> <span class="pl-k">import</span> <span class="pl-v">MaskedArray</span>
....
<span class="pl-c1">&lt;</span><span class="pl-s1">rest</span> <span class="pl-s1">of</span> <span class="pl-s1">your</span> <span class="pl-s1">code</span><span class="pl-c1">&gt;</span></pre></div>
<h4 dir="auto">Expected Results</h4>
<p dir="auto">No exception or a warning with an alternative solution to the above issue. A depreciation message if the class has been removed.</p>
<p dir="auto">Although, from <a href="https://github.com/scikit-learn/scikit-learn/blob/master/sklearn/utils/fixes.py#L20">https://github.com/scikit-learn/scikit-learn/blob/master/sklearn/utils/fixes.py#L20</a> it appears that this is due to be removed in <code class="notranslate">0.25.0</code>.</p>
<h4 dir="auto">Actual Results</h4>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="ImportError while importing test module '/opt/atlassian/pipelines/agent/build/tests_package_name/module.py'.
Hint: make sure your test modules/packages have valid Python names.
Traceback:
tests/test_package_name.py:7: in &lt;module&gt;
    from package_name import H2OGradientBoostingModel
package_name/module.py:5: in &lt;module&gt;
    from skopt import gp_minimize
/usr/local/lib/python3.6/site-packages/skopt/__init__.py:54: in &lt;module&gt;
    from .searchcv import BayesSearchCV
/usr/local/lib/python3.6/site-packages/skopt/searchcv.py:16: in &lt;module&gt;
    from sklearn.utils.fixes import MaskedArray
E   ImportError: cannot import name 'MaskedArray'"><pre class="notranslate"><code class="notranslate">ImportError while importing test module '/opt/atlassian/pipelines/agent/build/tests_package_name/module.py'.
Hint: make sure your test modules/packages have valid Python names.
Traceback:
tests/test_package_name.py:7: in &lt;module&gt;
    from package_name import H2OGradientBoostingModel
package_name/module.py:5: in &lt;module&gt;
    from skopt import gp_minimize
/usr/local/lib/python3.6/site-packages/skopt/__init__.py:54: in &lt;module&gt;
    from .searchcv import BayesSearchCV
/usr/local/lib/python3.6/site-packages/skopt/searchcv.py:16: in &lt;module&gt;
    from sklearn.utils.fixes import MaskedArray
E   ImportError: cannot import name 'MaskedArray'
</code></pre></div>
<h4 dir="auto">Versions</h4>
<p dir="auto">0.23.0</p>
<p dir="auto">In scikit-learn 0.23.0:</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="&gt;&gt;&gt; import skopt
Traceback (most recent call last):
  File &quot;&lt;stdin&gt;&quot;, line 1, in &lt;module&gt;
  File &quot;venv/lib/python3.6/site-packages/skopt/__init__.py&quot;, line 54, in &lt;module&gt;
    from .searchcv import BayesSearchCV
  File &quot;venv/lib/python3.6/site-packages/skopt/searchcv.py&quot;, line 16, in &lt;module&gt;
    from sklearn.utils.fixes import MaskedArray
ImportError: cannot import name 'MaskedArray'"><pre class="notranslate"><code class="notranslate">&gt;&gt;&gt; import skopt
Traceback (most recent call last):
  File "&lt;stdin&gt;", line 1, in &lt;module&gt;
  File "venv/lib/python3.6/site-packages/skopt/__init__.py", line 54, in &lt;module&gt;
    from .searchcv import BayesSearchCV
  File "venv/lib/python3.6/site-packages/skopt/searchcv.py", line 16, in &lt;module&gt;
    from sklearn.utils.fixes import MaskedArray
ImportError: cannot import name 'MaskedArray'
</code></pre></div>
<p dir="auto">There was no deprecation warning in earlier version - now any library that relied on this (e.g. scikit optimize) is broken.</p>