Hi Paul, Seems like on line 154 in the Makefile:
> ifneq ($(MACHINE),$(filter $(MACHINE),ibms390 s390)) > override CFLAGS += $(foreach flag,-fmodulo-sched,$(cc_supports_flag)) > endif the variable $(MACHINE) is receiving the value 'make[1]: Entering directory ... s390 make[1]: Leaving directory ...' instead of just 's390'. This causes the if condition to execute causing the `-fmodulo-sched` flag to be enabled triggering the issue. running make with --no-print-directory seems to fix the issue. So, maybe a simple change in the rules file should do. But at the same time, although it doesn't make much sense to enable `-fmodulo-sched` in an out-of-order architecture like s390x, it shouldn't cause the compiler to loop indefinitely. So, I will try to extract a test case where I can reproduce the issue and will try to communicate with the compiler team here at IBM. Either ways, that if condition is not supposed to run. I tried doing an sbuild after adding --no-print-directory in the rules file and with that it seems to build fine (autopkgtest also passes). Thanks, Pranav
