<p dir="auto">GitHub Actions MacOS CI jobs have been failing consistently. A sample log is available here: <a href="https://github.com/scipy/scipy/pull/13094/checks?check_run_id=1436142836">https://github.com/scipy/scipy/pull/13094/checks?check_run_id=1436142836</a></p>
<p dir="auto">SciPy itself is built successfully, but runtime access to gfortran dynamic libraries (via openblas lib) is compromised, causing a cascade of failures during the testsuite that look like this:</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="E   ImportError: dlopen(/Users/runner/work/scipy/scipy/build/testenv/lib/python3.8/site-packages/scipy/spatial/qhull.cpython-38-darwin.so, 2): Library not loaded: /libgfortran.3.dylib
E     Referenced from: /Users/runner/work/scipy/scipy/openblas/lib/libopenblasp-r0.3.9.dylib
E     Reason: image not found
_ ERROR collecting build/testenv/lib/python3.8/site-packages/scipy/cluster/tests/test_hierarchy.py _
ImportError while importing test module '/Users/runner/work/scipy/scipy/build/testenv/lib/python3.8/site-packages/scipy/cluster/tests/test_hierarchy.py'."><pre class="notranslate"><code class="notranslate">E   ImportError: dlopen(/Users/runner/work/scipy/scipy/build/testenv/lib/python3.8/site-packages/scipy/spatial/qhull.cpython-38-darwin.so, 2): Library not loaded: /libgfortran.3.dylib
E     Referenced from: /Users/runner/work/scipy/scipy/openblas/lib/libopenblasp-r0.3.9.dylib
E     Reason: image not found
_ ERROR collecting build/testenv/lib/python3.8/site-packages/scipy/cluster/tests/test_hierarchy.py _
ImportError while importing test module '/Users/runner/work/scipy/scipy/build/testenv/lib/python3.8/site-packages/scipy/cluster/tests/test_hierarchy.py'.
</code></pre></div>
<p dir="auto">There are quite a few shims in that CI code that deal with dynamic library behavior--I'll try to check this today as it will be important for CI to be consistently green with 1.6.0 branching imminent. If someone else is already close to a solution please chime in to avoid duplicated effort.</p>
<p dir="auto">I had  made  two np arrays xxx &amp; yyy:                          (*** are later edits)</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="&gt;&gt;&gt; len(xxx)
22092
&gt;&gt;&gt; len(yyy)
22092
&gt;&gt;&gt; def myfn(x, a, b):
...     return a*exp( -b*x)
...

&gt;&gt;&gt; optimize.curve_fit(myfn, xxx, yyy)
Traceback (most recent call last):
  File &quot;&lt;stdin&gt;&quot;, line 1, in &lt;module&gt;
  File &quot;/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/scipy/optimize/minpack.py&quot;, line 506, in curve_fit
    res = leastsq(func, p0, args=args, full_output=1, **kw)
  File &quot;/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/scipy/optimize/minpack.py&quot;, line 348, in leastsq
    m = _check_func('leastsq', 'func', func, x0, args, n)[0]
  File &quot;/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/scipy/optimize/minpack.py&quot;, line 14, in _check_func
    res = atleast_1d(thefunc(*((x0[:numinputs],) + args)))
  File &quot;/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/scipy/optimize/minpack.py&quot;, line 418, in _general_function
    return function(xdata, *params) - ydata
  File &quot;&lt;stdin&gt;&quot;, line 2, in myfn
TypeError: only length-1 arrays can be converted to Python scalars ************"><pre class="notranslate"><code class="notranslate">&gt;&gt;&gt; len(xxx)
22092
&gt;&gt;&gt; len(yyy)
22092
&gt;&gt;&gt; def myfn(x, a, b):
...     return a*exp( -b*x)
...

&gt;&gt;&gt; optimize.curve_fit(myfn, xxx, yyy)
Traceback (most recent call last):
  File "&lt;stdin&gt;", line 1, in &lt;module&gt;
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/scipy/optimize/minpack.py", line 506, in curve_fit
    res = leastsq(func, p0, args=args, full_output=1, **kw)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/scipy/optimize/minpack.py", line 348, in leastsq
    m = _check_func('leastsq', 'func', func, x0, args, n)[0]
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/scipy/optimize/minpack.py", line 14, in _check_func
    res = atleast_1d(thefunc(*((x0[:numinputs],) + args)))
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/scipy/optimize/minpack.py", line 418, in _general_function
    return function(xdata, *params) - ydata
  File "&lt;stdin&gt;", line 2, in myfn
TypeError: only length-1 arrays can be converted to Python scalars ************
</code></pre></div>
<h1 dir="auto"></h1>
<p dir="auto">*******  So I tried to duplicate the example in the scipy documentation:<br>
******* Failure on the second line!<br>
******* It's not really a curve_fit problem ****</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="&gt;&gt;&gt; def myfn(x, a, b):
...     return a*exp( -b*x)
...
&gt;&gt;&gt; tstx=np.linspace(0, 4, 50)
&gt;&gt;&gt; tsty=myfn(tstx,2.5, 1.3)
Traceback (most recent call last):
  File &quot;&lt;stdin&gt;&quot;, line 1, in &lt;module&gt;
  File &quot;&lt;stdin&gt;&quot;, line 2, in myfn
TypeError: only length-1 arrays can be converted to Python scalars ************
&gt;&gt;&gt;"><pre class="notranslate"><code class="notranslate">&gt;&gt;&gt; def myfn(x, a, b):
...     return a*exp( -b*x)
...
&gt;&gt;&gt; tstx=np.linspace(0, 4, 50)
&gt;&gt;&gt; tsty=myfn(tstx,2.5, 1.3)
Traceback (most recent call last):
  File "&lt;stdin&gt;", line 1, in &lt;module&gt;
  File "&lt;stdin&gt;", line 2, in myfn
TypeError: only length-1 arrays can be converted to Python scalars ************
&gt;&gt;&gt;
</code></pre></div>
<h1 dir="auto"></h1>
<p dir="auto">What have I done wrong?</p>
<p dir="auto">Thanks for any help</p>
<p dir="auto">Peter R<br>
~</p>