What is the meaning of this message and if it is a problem how can I solve it? I think it can be linked to the issue below.
I had to remove brew and reinstall it. I am still using Mac OS 10.11 and am aware that brew is unsupported in this version. Now I can not install any package with brew because git will not build with this error:
git-credential-osxkeychain.c:4:10: fatal error: 'Security/Security.h' file not found
Seems that the brew build environment does not include the Frameworks in the headers path.