$ cat test.asm %imacro mac 1-2 j%+1 %endmacro mac c, label $ nasm -v NASM version 2.15rc0 compiled on Oct 29 2019 $ nasm test.asm Segmentation fault $ oldnasm -v NASM version 2.14.03rc2 compiled on Aug 31 2019 $ oldnasm test.asm test.asm:4: error: invalid combination of opcode and operands test.asm:2: ... from macro `mac' defined here $ /usr/bin/nasm -v NASM version 2.12.01 $ /usr/bin/nasm test.asm test.asm:4: error: invalid combination of opcode and operands $