Conrad (of Armadillo fame) sent me this (and ok'ed passing it on):
According to an Intel report back from 2011, -Bsymbolic-functions "is a dangerous option which can often result in some non-intuitive side effects". The report explicitly shows various problems with the option. https://software.intel.com/content/www/us/en/develop/articles/performance-tools-for-software-developers-bsymbolic-can-cause-dangerous-side-effects.html In the light of the above, it's a real wonder that Ubuntu uses the option at all. Perhaps Ubuntu developers meant well, but are not aware of the side effects ? Graham do you think you can get it turned off for at least openblas? Dirk -- http://dirk.eddelbuettel.com | @eddelbuettel | e...@debian.org