Getting `Segmentation fault: 11` upon node crash (on regularly basis)

[DMXL]

System Info

• node version: v8.13.0
• npm or yarn version: v6.4.1
• OS/version/architecture: macOS 10.14.1
• Applicable nodegit version: v0.23.0

Description

I went through all related issues closed/open. At first I thought it might be problems with Remote#push, then I found out that commit and stage are also causing node to crash with the same error.

Real trouble is this happens randomly, sometimes after 2 or 3 times of API calling, other times just straight-down crashes on the first call. I even tried to monitor v8 heap/CPU usage, nothing suspicious was found though.

Reinstalling node and node modules didn't work either, but I'm guessing it's still most likely a compatibility issue with node. Any help is appreciated.

Code

The code is posted as follows, in case there is something wrong with the way APIs are called:

const git = require('nodegit')
// ...
const repoInstance = await git.Repository.open(rootPath)
const repoRemote = await repoInstance.getRemote('origin')
const author = git.Signature.now(username, email)
const cred = git.Cred.userpassPlaintextNew(username, password)

const signature = '\nauto commit --ignore'
const commitMessage = `Modify file ${relPath}${signature}`

await repoInstance.stageFilemode(relPath, true)
await repoInstance.createCommitOnHead([relPath], author, author, commitMessage)
return repoRemote.push(['refs/heads/master:refs/heads/master'], {
  callbacks: {
    credentials () {
      return cred
    }
  }
})

[implausible]

Is this code run in complete isolation or can we expect other things to be running in parallel?

[DMXL]

This is all the API does. So I guess it depends on the API calls being in parallel or not.

[JoyceBabu]

I am also getting the same error with just the following code

const nodegit = require('nodegit');
nodegit.Repository.open('./').then(function (repo) {
  // Inside of this function we have an open repo
  // console.log(repo);
});

exits with

Segmentation fault: 11

[implausible]

Can you hook up segfault-handler to your project or a debugger and see where it segfaults?

[JoyceBabu]

I tried the following code, but it just hangs

var SegfaultHandler = require('segfault-handler');

SegfaultHandler.registerHandler("crash.log");

const nodegit = require('nodegit');
nodegit.Repository.open('./').then(function (repo) {
  // Inside of this function we have an open repo
  // console.log(repo);
});

GDB

(gdb) run test.js
Starting program: /Users/joyce/.nvm/versions/node/v11.7.0/bin/node test.js
[New Thread 0xd03 of process 69559]
During startup program terminated with signal ?, Unknown signal.

LLDB

(lldb) run test.js
Process 69577 launched: '/Users/joyce/.nvm/versions/node/v11.7.0/bin/node' (x86_64)
Process 69577 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x104a80230)
    frame #0: 0x00000001009fba6c node`uv__async_close + 23
node`uv__async_close:
->  0x1009fba6c <+23>: movq   %rcx, 0x8(%rax)
    0x1009fba70 <+27>: movl   0x58(%rdi), %eax
    0x1009fba73 <+30>: testb  $0x4, %al
    0x1009fba75 <+32>: je     0x1009fba8a               ; <+53>
Target 0: (node) stopped.

[Unimax]

the problem looks like to be with return cred it seems we no longer able to reuse the cred object. possible solution could be creating new cred object every time. I solved the issue for me with something like: return Git.Cred.userpassPlaintextNew(getUsername(), getPassword())

[implausible]

Yes, I can confirm that what Unimax says is correct. In particular, it's because cred objects are owned by libgit2 after they are given to libgit2 through a credentials callback. It's a particularly nasty issue to solve as far as garbage collection and JS object safety goes.

[JoyceBabu]

Is mine a different issue? Should I create a new GitHub issue?

[lal12]

Yes, I can confirm that what Unimax says is correct. In particular, it's because cred objects are owned by libgit2 after they are given to libgit2 through a credentials callback. It's a particularly nasty issue to solve as far as garbage collection and JS object safety goes.

Wouldn't it be possible to just have a JS wrapper object, which will create an Cred instance as needed?