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BUG: BLAS detection assumes Debian/Ubuntu specific changes with unknown symbol from cblas #25028
Description
Describe the issue:
Building NumPy 1.26.1 on openSUSE results in a module that builds fine, but when importing it results in an unknown symbol:
[ 234s] ImportError:
[ 234s]
[ 234s] IMPORTANT: PLEASE READ THIS FOR ADVICE ON HOW TO SOLVE THIS ISSUE!
[ 234s]
[ 234s] Importing the numpy C-extensions failed. This error can happen for
[ 234s] many reasons, often due to issues with your setup or how NumPy was
[ 234s] installed.
[ 234s]
[ 234s] We have compiled some common reasons and troubleshooting tips at:
[ 234s]
[ 234s] https://numpy.org/devdocs/user/troubleshooting-importerror.html
[ 234s]
[ 234s] Please note and check the following:
[ 234s]
[ 234s] * The Python version is: Python3.9 from "/usr/bin/python3.9"
[ 234s] * The NumPy version is: "1.26.1"
[ 234s]
[ 234s] and make sure that they are the versions you expect.
[ 234s] Please carefully study the documentation linked above for further help.
[ 234s]
[ 234s] Original error was: /home/abuild/rpmbuild/BUILDROOT/python-numpy-1.26.1-0.x86_64/usr/lib64/python3.9/site-packages/numpy/core/_multiarray_umath.cpython-39-x86_64-linux-gnu.so: undefined symbol: cblas_sgemm
I think this is because of a Debian-specific change, in /usr/share/doc/libblas-dev/README.if-you-look-for-libcblas.so.3:
Debian science team maintainers have merged the CBLAS ABI into
the libblas.so shared object. Everything you need from libcblas.so
can be found in libblas.so . Please link your program against it
instead.
Due to that change, linking against -lblas is absolutely fine, and works -- it's currently passing in your CI. However, other distributions are likely not doing the same. I can probably work around this by using blas-order=cblas, but I also thought I'd make you aware of that distribution-specific change as well.
Reproduce the code example:
<None required>Error message:
No response
Runtime information:
NumPy 1.26.1
openSUSE Tumbleweed 20231026
Context for the issue:
No response
Activity
rgommers commentedon Oct 31, 2023
Thank you for the report @s-t-e-v-e-n-k. You are completely correct, I was unaware that Debian did this and hence relied on a CI job to test Netlib BLAS that didn't cover the split libblas/libcblas situation. We'll get this fixed soon and backported for 1.26.2.
rgommers commentedon Oct 31, 2023
@s-t-e-v-e-n-k I'm building a CI job based on the
opensuse/tumbleweedDocker container, and it looks like for BLAS there isn't a pkg-config file installed - is that right?I used this to install the system dependencies:
s-t-e-v-e-n-k commentedon Oct 31, 2023
Sadly, yes. It's being worked on. You'll need
lapack-develas well, but the lack of.pcfiles is known.