<p dir="auto">Hi,</p>
<p dir="auto">I've noticed that numpy's testsuite hangs when numpy is built against MKL 2018.2 - but runs to completion when built against MKL 2017.1.</p>
<p dir="auto">This is the case for numpy v1.14.2, 1.14.x HEAD and master branches.</p>
<p dir="auto">I'm on CentOS 7.4 x86_64 on a Broadwell processor, python 2.7.5 (but also affects other pythons), Cython 0.28.2, nose 1.3.7.</p>
<p dir="auto">By executing this: python -c "import numpy; numpy.test(verbose=2)"</p>
<p dir="auto">I can see that the hang occurs while running this test: numpy.distutils.tests.test_exec_command.TestExecCommand.test_basic</p>
<p dir="auto">At this point, the python interpreter is consuming an entire CPU core and, if I strace it, I see a stream of identical lines, all showing:</p>
<p dir="auto">sched_yield()                           = 0</p>
<p dir="auto">Any ideas, please?</p>
<p dir="auto">Thanks!</p>
<p dir="auto">Hello!</p>
<p dir="auto">Linux Mint: 18.3 (Sylvia)<br>
Python: 3.6.3<br>
NumPy: 1.13.3<br>
Cython 0.27.3</p>
<p dir="auto">I am trying to build numpy and scipy wheels from source using the intel mkl compilers. Numpy compiles just fine, however when I run the test suite, the suite hangs on <code class="notranslate">test_path_type_input</code> within <code class="notranslate">test_einsum.TestEinSumPath</code> (or maybe the test after it? not sure because the last test name visible is this one; see screen cap)</p>
<p dir="auto">Running the test suite for scipy results in the suite hanging on <code class="notranslate">test_lapack</code> within <code class="notranslate">test_build.TestF77Mismatch</code></p>
<p dir="auto">In both cases (numpy and scipy) the tests run and pass fine when run individually, so I'm not sure what else might be the cause.</p>
<p dir="auto">Any help is greatly appreciated. See screen shot for images of the test suites when they're stuck is included.<br>
<a target="_blank" rel="noopener noreferrer nofollow" href="https://user-images.githubusercontent.com/7530947/33036734-90a4cba6-cdec-11e7-8014-025c4f0904f1.png"><img src="https://user-images.githubusercontent.com/7530947/33036734-90a4cba6-cdec-11e7-8014-025c4f0904f1.png" alt="numpy" style="max-width: 100%;"></a><br>
<a target="_blank" rel="noopener noreferrer nofollow" href="https://user-images.githubusercontent.com/7530947/33036738-92df0c24-cdec-11e7-93f7-0b0417779e7c.png"><img src="https://user-images.githubusercontent.com/7530947/33036738-92df0c24-cdec-11e7-93f7-0b0417779e7c.png" alt="scipy" style="max-width: 100%;"></a></p>