Addition of ppa repository failing intermittently

I am also facing similar issue with add repository with different ppa packages from last few days:

Cannot add PPA: 'ppa:~criu/ubuntu/ppa'.
The team named '~criu' has no PPA named 'ubuntu/ppa'
Please choose from the following available PPAs:
* 'ppa': CRIU PPA

Status changed to 'Confirmed' because the bug affects multiple users.

The correct PPA naming is ppa:longsleep/golang-backports and ppa:criu/ppa without tilde character and without "/ubuntu" in the middle.

Eventually the code of the script should be modified to cater for usage with wrong-named PPAs.

I facing this issue while doing just

    apt-add-repository -y 'ppa:hvr/ghc'

i.e. no `/ubungu` nor tilde. This is on Ubuntu 18.04, so maybe it's old apt-add-repository which does some rewriting?

E.g. in fresh buildpack-deps:bionic Docker container this fails 100% of the time

    apt-get update
    apt-get install -y --no-install-recommends gnupg ca-certificates dirmngr curl git software-properties-common libtinfo5
    apt-add-repository -y 'ppa:hvr/ghc'

Either with JSONDecodeError or with "Cannot add PPA: 'ppa:~hvr/ubuntu/ghc'."

EDIT: seems to work on focal.

I am seeing this on focal, when running command:

$ add-apt-repository ppa:snappy-dev/image -y

on 20.04. 22.04 seems to be fine.

The errors I see are of the same two types as those in the bug description:

<<
Cannot add PPA: 'ppa:~snappy-dev/ubuntu/image'.
The team named '~snappy-dev' has no PPA named 'ubuntu/image'
Please choose from the following available PPAs:
 * '15.04': DEPRECATED - WILL REMOVE SOON (Tools for Snappy 15.04)
 * 'beta': Snappy beta
 * 'edge': Snappy Edge
 * 'image': Packages used in constructing the Ubuntu Core component of Snappy
...
>>

or the backtrace:

<<
Traceback (most recent call last):
  File "/usr/bin/add-apt-repository", line 137, in <module>
    shortcut = shortcut_handler(line)
  File "/usr/lib/python3/dist-packages/softwareproperties/SoftwareProperties.py", line 885, in shortcut_handler
    ret = factory(shortcut)
  File "/usr/lib/python3/dist-packages/softwareproperties/ppa.py", line 469, in shortcut_handler
    return PPAShortcutHandler(shortcut)
  File "/usr/lib/python3/dist-packages/softwareproperties/ppa.py", line 426, in __init__
    info = get_ppa_info(self.shortcut)
  File "/usr/lib/python3/dist-packages/softwareproperties/ppa.py", line 392, in get_ppa_info
    _get_suggested_ppa_message(user, ppa))
  File "/usr/lib/python3/dist-packages/softwareproperties/ppa.py", line 349, in _get_suggested_ppa_message
    lp_user = get_info_from_lp(LAUNCHPAD_USER_API % user)
  File "/usr/lib/python3/dist-packages/softwareproperties/ppa.py", line 104, in get_info_from_lp
    return get_info_from_https(lp_url, True)
  File "/usr/lib/python3/dist-packages/softwareproperties/ppa.py", line 98, in get_info_from_https
    return json.loads(data)
  File "/usr/lib/python3.8/json/__init__.py", line 357, in loads
    return _default_decoder.decode(s)
  File "/usr/lib/python3.8/json/decoder.py", line 337, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File "/usr/lib/python3.8/json/decoder.py", line 355, in raw_decode
    raise JSONDecodeError("Expecting value", s, err.value) from None
json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)
>>

The root cause of this is "Launchpad API randomly returns empty responses" https://bugs.launchpad.net/launchpad/+bug/2039251

Thanks @nosnilmot