> When I replace 'paxctl -zex' with 'paxctl +a' in src/Makefile.in, the
> build succeeds.

Did you do something other than just that replacement? configure.ac says 
that paxctl is used only when the operating system is GNU/Linux, unless 
one manually configures by setting PAXCTL in the environment or using a 
PAXCTL=/some/path argument to 'configure'.


Does the attached patch to the emacs-25 branch work for you?