transfer-issues.sh

#!/bin/bash

set -e

from=$1
to=$2

while read -r issue_json; do
    title=$(echo "$issue_json" | jq -r .title)
    number=$(echo "$issue_json" | jq -r .number)
    repo_name=$(basename "$from")
    new_title="[${repo_name}] ${title}"
    new_url=$(gh issue transfer --repo "$from" "$number" "$to")
    new_number=$(basename "$new_url")
    gh issue edit "$new_number" --repo "$to" --title "$new_title"
    echo "Transferred '$title' from $from to $to: https://$to/issues/$new_number"
    sleep 1
done < <(gh issue list --repo "$from" --json number,title --jq '.[]' -s open -L 10000)

Should this also change the issue title, e.g. by prepending the name of the repo where this issue originated?

Good idea, thanks! Added