Describe the bug

I'm doing the LIEF tutorial. I'm at 03 - Play with Elf, but after swapping the symbol names in the main executable and trying to run it I get:

./bin/hashme.obf: symbol lookup error: ./bin/hashme.obf: undefined symbol: cos, version GLIBC_2.2

To Reproduce

I have created a minimal reproducible example with a .devcontainer. But the python script is basically just a copy/paste from the tutorial:

#!/usr/bin/env python3
import lief

hashme = lief.parse("bin/hashme")
libm  = lief.parse("/usr/lib/x86_64-linux-gnu/libm.so.6")

def swap(obj, a, b):
    symbol_a = next(i for i in obj.dynamic_symbols if i.name == a)
    symbol_b = next(i for i in obj.dynamic_symbols if i.name == b)
    b_name = symbol_b.name
    symbol_b.name = symbol_a.name
    symbol_a.name = b_name

hashme_pow_sym = next(i for i in hashme.imported_symbols if i.name == "pow")
hashme_log_sym = next(i for i in hashme.imported_symbols if i.name == "log")

hashme_pow_sym.name = "cos"
hashme_log_sym.name = "sin"


swap(libm, "log", "sin")
swap(libm, "pow", "cos")

hashme.write("bin/hashme.obf")
libm.write("bin/libm.so.6")

main executable:

// gcc main.c -o bin/hashme -lm

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

double hashme(double input) {
  return pow(input, 4) + log(input + 3);
}

int main(int argc, char** argv) {
  if (argc != 2) {
    printf("Usage: %s N\n", argv[0]);
    return EXIT_FAILURE;
  }

  double N = (double)atoi(argv[1]);
  double hash = hashme(N);
  printf("%f\n", hash);

  return EXIT_SUCCESS;
}

1. Build the main executable: gcc main.c -o bin/hashme -lm
2. Run the infect script (might have to adjust for libm location): python infect.py
3. Make hashme.obf executable: chmod +x bin/hashme.obf
4. Run bin/hashme.obf
5. Observe the error: bin/hashme.obf: symbol lookup error: bin/hashme.obf: undefined symbol: cos, version GLIBC_2.29

When opening the bin/hashme.obf file in IDA I get the following warning:

Unexpected entries in the PLT stub.
The file might have been modified after linking.

EDIT: Turns out this error is displayed in IDA even when opening the normal (unmodified) hashme executable, so it is unrelated to LIEF. Not sure why I get that warning but that doesn't seem relevant to the issue I have.

Expected behavior

I should still be able to run the main executable, as the tutorial shows.

Environment (please complete the following information):

• System and Version : Ubuntu 22.04 in Docker, running on WLS2
• Target format : ELF
• LIEF commit version: 0.15.0-54d0a72c