pwntools giving me this error only for the 32 bit elf file for 64bit everything works fine:
Could not find any instructions in ['int 0x80']

i wrote a small vuln server in c and use some inline assembly to generate for gadgets for my own example:

asm volatile(
    "int $0x80\n\t"
    "ret"
    :
);

ROPgadget output:

0x08049311 : int 0x80
0x08049311 : int 0x80 ; ret

so the gadget is still there but works only in 64bit