BUG: 1.8.1 openblas not found

[sashkab]

After back-porting #4191 into 1.8.1, openblas is not found on systems by default.

Backward compatibility logic is wrong.

diff --git a/numpy/distutils/system_info.py b/numpy/distutils/system_info.py
index fbdd164..35aba17 100644
--- a/numpy/distutils/system_info.py
+++ b/numpy/distutils/system_info.py
@@ -1565,7 +1565,7 @@ class openblas_info(blas_info):
         lib_dirs = self.get_lib_dirs()

         openblas_libs = self.get_libs('libraries', self._lib_names)
-        if openblas_libs == self._lib_names: # backward compat with 1.8.0
+        if openblas_libs == []: # backward compat with 1.8.0
             openblas_libs = self.get_libs('openblas_libs', self._lib_names)
         info = self.check_libs(lib_dirs, openblas_libs, [])
         if info is None:

[juliantaylor]

looks more like a bug in system_info it sets the global default of the libraries keys to '' breaking the default setting of the get_libs function
workaround is to use the libraries key instead of the 1.8.0 only openblas_libs key which is deprecated.

[sashkab]

Still, this is a bug, which needs to be addressed. Based on what I understood from the code, there is zero libraries which will get detected. Having both atlas and openblas installed on one of the systems, I was getting NOT FOUND for all.