--- current/macros.orig	2017-10-11 13:34:32.288393926 +0200

+++ current/macros	2017-10-11 13:34:44.519416133 +0200

@@ -74,7 +74,12 @@

   install

 # Maximum number of CPU's to use when building, 0 for unlimited.

-%_smp_ncpus_max 16

+#                                                                              

+# This was for some time capped at 16.  Please see                             

+# https://bugzilla.redhat.com/show_bug.cgi?id=669638 and                       

+# https://bugzilla.redhat.com/show_bug.cgi?id=1384938 for the situation        

+# surrounding this.                                                            

+#%_smp_ncpus_max 0   

 %_smp_mflags %([ -z "$RPM_BUILD_NCPUS" ] \\\

 	&& RPM_BUILD_NCPUS="`/usr/bin/getconf _NPROCESSORS_ONLN`"; \\\

         ncpus_max=%{?_smp_ncpus_max}; \\\