Cannot easy install in ubuntu 18.04 with last given error/warning "Could not find aptitude. Using apt-get instead"

Issue: Easy Install

**Do the checklist before filing an issue:**
- [x] Did you retain the logfile (path of logfile is shared while the script is run)? We definitely **need** the logfile to debug any easy install related issues.
- [ ] Is this something you can debug and fix? Send a pull request! Bug fixes and documentation fixes are welcome

**Distro Information (Required)**

1. uname -a
Linux ubuntu1 4.15.0-112-generic frappe/bench#113-Ubuntu SMP Thu Jul 9 23:41:39 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
2. cat /etc/*-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=18.04
DISTRIB_CODENAME=bionic
DISTRIB_DESCRIPTION="Ubuntu 18.04.4 LTS"
NAME="Ubuntu"
VERSION="18.04.4 LTS (Bionic Beaver)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 18.04.4 LTS"
VERSION_ID="18.04"
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
VERSION_CODENAME=bionic
UBUNTU_CODENAME=bionic

**Command Run (Required)**
I am completely following the wiki: https://github.com/frappe/bench#easy-install-script, and when I reached the step - run the command "python3 install.py --production", the error came out.

**Log File (Required)**
Upload
[easy-install__2020-08-19__09-00.log](https://github.com/frappe/bench/files/5095293/easy-install__2020-08-19__09-00.log)
[easy-install__2020-08-19__09-02.log](https://github.com/frappe/bench/files/5095294/easy-install__2020-08-19__09-02.log)

**Screenshots**

**Additional context**
It's a fresh install of ubuntu 18.04 on Virtualbox(using official site iso image, Virtualbox configuration is x86_64 with 2 CPU cores, 2GB RAM and 20GB Drive), and completely followed the wiki: https://github.com/frappe/bench#easy-install-script

**Possible Solution**
Sorry I am not sure, but thank anyone who will be willing to look at this issue.