Decrease deb-get update verbositty

[yermulnik]

Requesting a new feature 🧑‍💻

Apparently since the change in #737 PR deb-get started to output extraneous info to stderr from wget and curl («fetching non-github repo») and to stdout from cd - command (all within update_repos() function) — the output between [+] Updating /etc/deb-get/01-main and [---cut---] lines (which is where starts usual informational output which are not related to this request):

> deb-get update
  [+] Updating /etc/deb-get/01-main
/etc/deb-get/01-main.rep 100%[==================================>]   2,70K  --.-KB/s    in 0s
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
100  102k  100  102k    0     0   172k      0 --:--:-- --:--:-- --:--:--  172k
/home/giermulnik
[---cut---]

My use case is as simple as this — I want the list of packages pending updates to be emailed to me:

45 9 * * * root deb-get update | fgrep 'has an update pending.'

though I don't want extra output to be emailed every deb-get cron job run. I also would prefer to not redirect stderr to /dev/null or a file as this would hide any potential errors which may occur during cron job run.

Can this output be silenced or enabled on-demand please?

How to fix (or make output optional via e.g. new deb-get update cmdline parameter):

• Removing --show-progress from wget cmdline prevents it from outputting download progress (this option forces the progress bar to be printed when --quiet/-q option is set)
• Adding -Ss to curl cmdline prevents it from outputting download progress (while still showing error messages)
• Replacing cd - with cd ~- prevents cd from outputting extra info about previous directory in stack while chdir'ing into it (UPD: Make update_repos cd quietly #759)

Expected behavior

• deb-get update doesn't produce extra output to sdterr/stdout like wit was before Speed mitigations with no heavy in-repo caching #737
• Extra output may be turned on or off via command line option.

Actual behavior

New extra output between [+] Updating /etc/deb-get/01-main and [---cut---] lines (which is where starts usual informational output which are not related to this request):

> deb-get update
  [+] Updating /etc/deb-get/01-main
/etc/deb-get/01-main.rep 100%[==================================>]   2,70K  --.-KB/s    in 0s
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
100  102k  100  102k    0     0   172k      0 --:--:-- --:--:-- --:--:--  172k
/home/giermulnik
[---cut---]

Steps to reproduce

Run the below and find extra output:

deb-get update | 'has an update pending.'

System information

Run the following a paste the output below:

/etc/os-release

> cat /etc/os-release
NAME="Ubuntu"
VERSION="20.04.5 LTS (Focal Fossa)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 20.04.5 LTS"
VERSION_ID="20.04"
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=focal
UBUNTU_CODENAME=focal

/etc/lsb-release

> cat /etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=20.04
DISTRIB_CODENAME=focal
DISTRIB_DESCRIPTION="Ubuntu 20.04.5 LTS"

deb-get version

> deb-get version
0.3.7