test/20230720.2$ cat test1.asm
%macro mmac 0
%rep 1

%endrep
%endmacro

mmac
test/20230720.2$ cat test2.asm
%macro mmac 0
%rep 1
%endrep
%endmacro

mmac
test/20230720.2$ orignasm -v
NASM version 2.17rc0 compiled on Jul 20 2023
test/20230720.2$ orignasm test1.asm
test/20230720.2$ orignasm test2.asm
panic: test2.asm:6: assertion fm == istk->mstk.mstk failed at asm/preproc.c:7568
test/20230720.2$ nasm -v
NASM version 2.17rc0 compiled on Jul 20 2023
test/20230720.2$ nasm test1.asm
test/20230720.2$ nasm test2.asm
panic: test2.asm:6: assertion fm == istk->mstk.mstk failed at asm/preproc.c:7568
test/20230720.2$