apt-add-repository returns "user or team does not exist." when erroring out due to proxy auth needed

[Sven]

I have just installed a fresh Ubuntu 15.10 to my machine and run into trouble with adding ppa repositories using apt-add-repository:

for e.g. running
apt-add-repository ppa:git-core/ppa
Cannot add PPA: 'ppa:~git-core/ubuntu/ppa'.
ERROR: '~git-core' user or team does not exist.

After debugging a lot of code, I found the trouble, the used proxy-server needs authentification but the apt-add-repository does not throw a correct error message fro this case:

The PPAException raised here seems to be interpreted as not available, which is rather hard to debug.

def _get_https_content_py3(lp_url):
    print("RETRIEVING URL: %s"%lp_url)
    try:
        request = urllib.request.Request(str(lp_url), headers={"Accept":" application/json"})
        lp_page = urllib.request.urlopen(request, cafile=LAUNCHPAD_PPA_CERT)
        json_data = lp_page.read().decode("utf-8", "strict")
        print(" RV: %s"%str(json_data))
    except (URLError, HTTPException) as e:
        # HTTPException doesn't have a reason but might have a string
        # representation
        print(e)
        reason = hasattr(e, "reason") and e.reason or e
        raise PPAException("Error reading %s: %s" % (lp_url, reason), e)

The last print(e) gives me the hint what went wrong:
<urlopen error Tunnel connection failed: 407 Proxy Authorization Required>

For the future it would be great to get a correct error message.

[Launchpad Janitor (janitor)]

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

[James Lewis (james-fsck)]

Just encountered this bug in 16.10, it reported the exact "user or team does not exist." error, until I added a system wide proxy.

[Ashish (ashish235)]

Hi @james,

Can you tell how did you add "system wide proxy"? I 'm having this issue too on 16.04.

[nPatel (narendrapatel)]

Just upgraded Ubuntu 16.04 LTS to 18.04.1 LTS. PPA that i added in previous version, can't add it in newer and result is same as mentioned by others "user or team does not exist."

[sun (leiiiiiiiiiiiiii)]

Hi,How did you finally solve this problem?
i am in add
sudo -E add-apt-repository ppa:mosquitto-dev/mosquitto-ppa
exception message:
Cannot add PPA: 'ppa:~mosquitto-dev/ubuntu/mosquitto-ppa'.
ERROR: '~mosquitto-dev' user or team does not exist.