How to pass a shell function to `git rebase --exec`

In bash, to pass a variable or function to a child process, you need to export it.

#!/bin/bash

f() { echo hello; }

# calling shell function `f` in child process
bash -c "f" # bash: f: command not found

# export the function
export -f f
bash -c "f" # "hello"

However, I can't seem to achieve the same result with git rebase --exec

#!/bin/bash

f() { echo hello; }

# export the function
export -f f
git rebase --exec "f" # does not work
git rebase --exec "bash -c 'f'" # does not work

I know I could declare the function inline: git rebase --exec 'f() { echo hello; }; f' or put the function in another script and call it: git rebase --exec './f.sh'

Is there a way to make it work? What am I missing?

Here is my solution. Thanks to @CharlesDuffy for his help.

#!/usr/bin/env bash

f() {
  for i in "$@"; do
    echo "$i"
  done
}

printf -v cmd_q '%q ' "$(declare -f f); f" # serialise function f
export cmd_q
printf -v args '%q ' "$@" # serialise arguments f
export args

# remove -r --root and adapt to your needs here
git rebase -r --root --exec $'bash -c "eval $cmd_q \'$args\'"'