Exploit a simple file with ROP chain using Python gdb script

The task is the following:

*(Please read README.md file for more details or direct message)

There are two binaries: vuln and execute_me_with_rop. There is a simple vulnerability in vuln. Your task is to build a ROP chain that executes execute_me_with_rop so that it prints the flag.

Use the execve system call and prepare all necessary arguments accordingly. You must not use pwntools' pwnlib.shellcraft for this exercise! You must also not just execve("/bin/sh -c './execute_me_with_rop arg1 arg2'") for the execution of execute_me_with_rop!
Edit the provided solution template and explain your approach with meaningful comments!

Hints: Try to write a C program first which executes execute_me_with_rop, to find out how to build your ROP chain:

#include <unistd.h>
int main() {
char* argv[] = { "./execute_me_with_rop" , "foo", "bar", NULL };
char* envp[] = { "PABE=FUN", NULL }; execve("./execute_me_with_rop", argv, envp);
return 0;
}

Remember how to set argv**

Hints on Leaking the address:

Try to leak the address of __libc_csu_init from the stack and calculate the file_base_addr.

Next, use the file_base_addr to build a small ROP-chain from the ./vuln which invokes puts-PLT and as an puts-GOT entry as its parameter and finally start the program again through the ROP-chain in oder to leak puts@GLIBC.