libxc @2.2.3 break other code due to compile parameter

[tczorro (Derrick)]

We use libxc as a dependence for our package, but we found the libxc broke our code if it is compiled with -O3 or something else. but it is completely fine if we compiled it with -O1. Could you please fix this bug in Macports.

[mf2k (Frank Schima)]

In the future, please fill in the Port field and Cc the port maintainers (port info --maintainers libxc), if any.

[dstrubbe (David Strubbe)]

Hi, please be more specific, so we can try to figure if there really is a bug here. What code? What kind of problem arose? What variants for libxc are you using? Did you run its testsuite?

[tczorro (Derrick)]

Replying to dstrubbe:

Hi, please be more specific, so we can try to figure if there really is a bug here. What code? What kind of problem arose? What variants for libxc are you using? Did you run its testsuite?

Some code in LibXC gives notably different results with -O3. -O1 is safe. The failing test is related to kernels, i.e. second order derivatives of the functionals, which are not used as frequently.

[dstrubbe (David Strubbe)]

Thanks, that's a little bit more info, but could you please answer my questions?

What code are you linking libxc to? What variants for libxc are you using? (I'm sure you're aware that what happens at -O3 vs -O1 is very dependent on the compiler and version.) If you ran the libxc testsuite, can you be specific about what tests failed?

[dstrubbe (David Strubbe)]

Information to define the problem was never provided.