When building a package that contains the %error macro, rpmbuild will print the
error but continue the build.

This makes it impossible to deliberately fail build, unless this is in
%prep/%build/%install, where one can put "exit 1" after the %error declaration.

The docs say:
%{error:...}    print ... to stderr and return BADSPEC

i don't know exactly what "return BADSPEC" means, but it is definitely not
doing what I expect


to reproduce:
take a working spec file and put %{error:hello world} somewhere in it

expected result:
rpmbuild fails, printing "Error: hello world"

actual result:
rpmbuild prints "Error: hello world" but the build finishes successfully