Can't login in headless multipass VM with 24.04
Metadata
Current evaluation
Open Charmcraft login failure on headless Ubuntu 24.04 Multipass VMs: Python selects keyring.backends.null.Keyring, so credentials cannot be retrieved; only a backend override is known.
Suggested action: needs triage
Reason: The exact Multipass commands, credential trace, null-backend probe, and working PYTHON_KEYRING_BACKEND workaround provide a strong reproduction, but all three comments are reporter-authored and there are no labels or maintainer response. Charmcraft currently falls back only when craft-store raises NoKeyringError; craft-store treats the fail backend as unavailable but does not handle the null backend, and no resolving change was found.
Evaluated by: mr-cal-bot
Impact:
54
Quick Win:
28
Complexity:
42
Confidence:
94
Actionability:
88
Issue body
### Bug Description
I can't seem to login with `charmcraft login` when I'm inside a headless 24.04 VM created with Multipass.
### To Reproduce
```bash
# create the VM
multipass launch 24.04 --name test --memory 4G --disk 5G --cpus 1
multipass shell test
# inside the VM
charcraft login
# I go to the browser and login, and then it crashes
# charmcraft internal error: CredentialsUnavailable("No credentials found for 'charmcraft' on 'api.charmhub.io'.")
```
### Environment
Headless VM with Ubuntu 24.04 and using the default channel of charmcraft
### charmcraft.yaml
```yaml
<none>
```
### Relevant log output
```shell
# from the produced log file
2025-04-30 10:53:40.188 HTTP 'POST' for 'https://api.charmhub.io/v1/tokens/exchange' with params None and headers {'Macaroons': '<macaroon>', 'User-Agent': 'Charmcraft/3.4.3 (Linux 6.8.0-58-generic; x86_64; CPython 3.10.12; Ubuntu 24.04)'}
2025-04-30 10:53:40.288 Storing credentials for 'charmcraft' on 'api.charmhub.io' in keyring 'null Keyring'.
2025-04-30 10:53:40.288 Retrieving credentials for 'charmcraft' on 'api.charmhub.io' from keyring 'null Keyring'.
2025-04-30 10:53:40.288 Credentials not found in the keyring 'null Keyring'
2025-04-30 10:53:40.289 charmcraft internal error: CredentialsUnavailable("No credentials found for 'charmcraft' on 'api.charmhub.io'.")
```
Evaluation history
| Date | Model | Scores | Action | Summary |
|---|---|---|---|---|
| stealth/space-bunny-alpha |
Impact:
54
Quick Win:
28
Complexity:
42
Confidence:
94
Actionability:
88
|
needs triage | Open Charmcraft login failure on headless Ubuntu 24.04 Multipass VMs: Python selects keyring.backends.null.Keyring, so credentials cannot be retrieved; only a backend override is known. | |
| ~deepseek/deepseek-pro-latest |
Impact:
50
Quick Win:
24
Complexity:
40
Confidence:
75
Actionability:
80
|
needs triage | charmcraft login fails in headless 24.04 multipass VM: keyring selects null Keyring, and craft-store only falls back to file keyring for fail.Keyring, not null.Keyring. Reporter provided root cause and workaround; no maintainer response yet. | |
| qwen/qwen3.6-35b-a3b |
Impact:
30
Quick Win:
14
Complexity:
40
Confidence:
80
Actionability:
80
|
keep open | charmcraft login fails on headless Ubuntu 24.04 VMs due to craft-store not handling the null keyring backend for credential storage. | |
| qwen/qwen3.8-27b |
Impact:
50
Quick Win:
28
Staleness:
70
Complexity:
45
Confidence:
65
Support Request:
25
|
needs triage | charmcraft login crashes in headless Multipass VMs (Ubuntu 24.04) because the keyring library falls back to the null keyring, so credentials can't be stored. Reporter self-diagnosed the gap in craft-store auth.py and shared a PYTHON_KEYRING_BACKEND workaround; no maintainer has responded. | |
| qwen/qwen3.6-35b-a3b |
Staleness:
85
Complexity:
30
Confidence:
80
Support Request:
10
|
close stale | Login fails in headless Ubuntu 24.04 VM due to keyring backend falling back to null. Author identified root cause in craft-store and provided a workaround. | |
| qwen3.6-35b-a3b-mtp-q6 |
Staleness:
85
Complexity:
50
Confidence:
85
Support Request:
20
|
needs triage | charmcraft login fails in headless Ubuntu 24.04 VMs because keyring defaults to null Keyring, blocking credential storage. Author identified the root cause in craft-store and provided a workaround. Awaiting maintainer review. | |
| qwen3.6-35b-a3b-mtp-q6 |
Staleness:
95
Complexity:
30
Confidence:
85
Support Request:
10
|
close stale | Bug where charmcraft login fails in headless Ubuntu 24.04 VMs due to keyring returning a null backend. Author provided a workaround and identified the root cause in an external dependency. Issue is over a year old with no maintainer engagement. |
Update history
No update history recorded yet.
Related work
-
Related To:
canonical/craft-store#236
(confidence 95%)
Added opt-in FileKeyring fallback, but the null backend remains outside that detection and Charmcraft does not enable file_fallback.
-
Related To:
canonical/charmcraft#1741
(confidence 90%)
Added ephemeral fallback for NoKeyringError; it is bypassed because the null backend does not raise that error.
Related issues
| Issue | Project | State | Summary | Similarity |
|---|---|---|---|---|
| #672 charmcraft 1.4.0: impossible to login to charmhub | charmcraft | closed | Closed as intended behavior: the headless remote host had no local keyring, so Charmcraft could not persist credentials; exporting credentials was the supported workaround. |