<p dir="auto">Seen on current main in job <code class="notranslate">ci/circleci: refguide_check</code>:</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="===================
scipy.sparse.linalg
===================

scipy.sparse.linalg.svds
------------------------

File &quot;build-install/lib/python3.9/site-packages/scipy/sparse/linalg/_eigen/_svds.py&quot;, line 280, in svds
Failed example:
    s_a(u2[:, :1], u[:, :1]) + s_a(u2[:, 1:], u[:, 1:]) &gt; 1e-3
Expected:
    True
Got:
    array([False])


File &quot;build-install/lib/python3.9/site-packages/scipy/sparse/linalg/_eigen/_svds.py&quot;, line 283, in svds
Failed example:
    (s_a(vT2[:1, :].T, vT[:1, :].T) +
     s_a(vT2[1:, :].T, vT[1:, :].T)) &gt; 1e-3
Expected:
    True
Got:
    array([False])


ERROR: refguide or doctests have errors"><pre class="notranslate"><code class="notranslate">===================
scipy.sparse.linalg
===================

scipy.sparse.linalg.svds
------------------------

File "build-install/lib/python3.9/site-packages/scipy/sparse/linalg/_eigen/_svds.py", line 280, in svds
Failed example:
    s_a(u2[:, :1], u[:, :1]) + s_a(u2[:, 1:], u[:, 1:]) &gt; 1e-3
Expected:
    True
Got:
    array([False])


File "build-install/lib/python3.9/site-packages/scipy/sparse/linalg/_eigen/_svds.py", line 283, in svds
Failed example:
    (s_a(vT2[:1, :].T, vT[:1, :].T) +
     s_a(vT2[1:, :].T, vT[1:, :].T)) &gt; 1e-3
Expected:
    True
Got:
    array([False])


ERROR: refguide or doctests have errors
</code></pre></div>
<p dir="auto">Both are <em>potentially</em> only marginal tolerance violations, AFAICT.</p>
<p dir="auto">An old similar issue I found while searching for this: <a class="issue-link js-issue-link" data-error-text="Failed to load title" data-id="1350652021" data-permission-text="Title is private" data-url="https://github.com/scipy/scipy/issues/16900" data-hovercard-type="issue" data-hovercard-url="/scipy/scipy/issues/16900/hovercard" href="https://github.com/scipy/scipy/issues/16900">#16900</a></p>
<h3 dir="auto">Describe your issue.</h3>
<p dir="auto">Lately I have seen the refguide job failing in CI multiple times in some sparse svd section: <a href="https://app.circleci.com/pipelines/github/scipy/scipy/19755/workflows/7be1af01-79dc-459c-92c4-d4a6d72c2471/jobs/66447" rel="nofollow">https://app.circleci.com/pipelines/github/scipy/scipy/19755/workflows/7be1af01-79dc-459c-92c4-d4a6d72c2471/jobs/66447</a></p>
<p dir="auto">Thought I would raise attention with a separate issue.</p>
<p dir="auto">Slightly related: it looks like the Fortran sparse SVD libraries are very painful to maintain. One unfortunately license incompatible alternative could be <a href="https://github.com/yixuan/spectra">Spectra</a>, ARPACK rewritten in C++. Are there any thoughts on replacements for the old PACKs?</p>
<h3 dir="auto">Reproducing Code Example</h3>
<div class="highlight highlight-source-python notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="N/A"><pre class="notranslate"><span class="pl-v">N</span><span class="pl-c1">/</span><span class="pl-v">A</span></pre></div>
<h3 dir="auto">Error message</h3>
<div class="highlight highlight-source-shell notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="File &quot;build-install/lib/python3.9/site-packages/scipy/sparse/linalg/_eigen/_svds.py&quot;, line 280, in svds
Failed example:
    s_a(u2[:, :1], u[:, :1]) + s_a(u2[:, 1:], u[:, 1:]) &gt; 1e-3
Expected:
    True
Got:
    array([False])

File &quot;build-install/lib/python3.9/site-packages/scipy/sparse/linalg/_eigen/_svds.py&quot;, line 283, in svds
Failed example:
    (s_a(vT2[:1, :].T, vT[:1, :].T) +
     s_a(vT2[1:, :].T, vT[1:, :].T)) &gt; 1e-3
Expected:
    True
Got:
    array([False])"><pre class="notranslate">File <span class="pl-s"><span class="pl-pds">"</span>build-install/lib/python3.9/site-packages/scipy/sparse/linalg/_eigen/_svds.py<span class="pl-pds">"</span></span>, line 280, <span class="pl-k">in</span> svds
Failed example:
    s_a(u2[:, :1], u[:, :1]) + s_a(u2[:, 1:], u[:, 1:]) <span class="pl-k">&gt;</span> 1e-3
Expected:
    True
Got:
    array([False])

File <span class="pl-s"><span class="pl-pds">"</span>build-install/lib/python3.9/site-packages/scipy/sparse/linalg/_eigen/_svds.py<span class="pl-pds">"</span></span>, line 283, <span class="pl-k">in</span> svds
Failed example:
    (s_a(vT2[:1, :].T, vT[:1, :].T) +
     s_a(vT2[1:, :].T, vT[1:, :].T)) <span class="pl-k">&gt;</span> 1e-3
Expected:
    True
Got:
    array([False])</pre></div>
<h3 dir="auto">SciPy/NumPy/Python version and system information</h3>
<div class="highlight highlight-source-shell notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="N/A"><pre class="notranslate">N/A</pre></div>