UnexpectedToken and DebugAllocator double free when generating stats in GitHub Actions

[genskyff]

Description

I followed the README to set up github-stats, but the GitHub Actions workflow fails at the Generate images step.

Command:

./zig-out/bin/github-stats

Error log:

error(DebugAllocator): Double free detected. Allocation:
(empty stack trace)
 First free:
(empty stack trace)
 Second free:
(empty stack trace)
error: UnexpectedToken
Error: Process completed with exit code 1.

6_Generate images.txt

Token setup

I created a classic personal access token and added it as the repository secret ACCESS_TOKEN.

The token has these permissions:

• read:user
• user:email
• repo

I also noticed some issues mentioning that a newly created token may take some time to work. However, I waited several days and reran the workflow, but the same error still occurs.

[jstrieb]

Hi @genskyff, thanks for taking the time to open this bug report! As far as I can tell, you're doing everything right here. Clearly there is a bug in my code, and likely there is an unexpected response from GitHub to one of the API calls.

Can you please re-run your workflow after removing --release from .github/workflows/main.yml on line 30, and changing the debug setting to true with DEBUG: "true" on line 48?

github-stats/.github/workflows/main.yml

Line 30 in 1f5843f

zig build --release

github-stats/.github/workflows/main.yml

Line 48 in 1f5843f

DEBUG: "false"

This should print more information about what the program is trying, and what is failing.

In the meantime, I'll do my own investigation as well to see if I can pinpoint what is happening.

---

Probably the root of this issue is the UnexpectedToken error, and then incorrect error handling causes the double free. In other words, the double free is probably a symptom and not a cause of the underlying issue.

I suspect there is unexpected data being passed to a JSON parse call, but that is just a guess. Sometimes this happens if the GitHub API returns invalid JSON for some reason, or if their response is not actually JSON at all. More information from your debug logs will be very helpful in getting to the bottom of this.

[genskyff]

Hi @jstrieb , thanks for the quick response!

I re-ran the workflow after removing --release and setting DEBUG: "true". I will attach the full debug log file separately.

The failure seems to happen while processing an external repository that is not under my own GitHub account. I have also removed that repository from my account/repository list, but I did contribute to it before by opening a PR. So it looks like github-stats still includes it because of my contribution history.

The Forbidden response when getting views makes sense to me, since I do not own/administer that repository. The issue seems to happen afterward, when getLinesChanged tries to process the same external repository and receives an unexpected response.

The full debug log also seems to confirm your suspicion: UnexpectedToken appears to be the root error, and the double free happens on the error path.

Please let me know if you want me to test anything else.

6_Generate images.txt

[jstrieb]

I believe I've fixed the double free.

Based on the log, the error is happening in a response from an API endpoint that has been giving me a lot of trouble recently. (For more, see this bug reported to GitHub.)

I may push a change allowing users to skip using that API entirely, since it seems to cause nothing but pain and heartache. In the meantime, you can set "max retries" to 0 instead of 5 in the workflow YAML file to mostly skip it. Also, I will push a fix that ignores parsing errors for that particular endpoint as a temporary workaround.

Let me know if you need any help pulling my fixes into your copy of the repo. It should just be a matter of replacing your statistics.zig with mine.

[genskyff]

Thanks for the quick fix!
I re-created the repository and re-ran the workflow, and it now works successfully on my side!

[jstrieb]

Glad it's back to working! I'll leave this issue open for a bit in case anyone else is experiencing the same problem. If nobody chimes in anytime soon, I'll close the issue.

Thanks again for the clear bug report, and for your willingness to work through the debugging!