bug: thread '<unknown>' has overflowed its stack

[junhwong]

Hi, i use tera with Rocket, run and crash of thread '' has overflowed its stack.
pls see: rwf2/Rocket#309

[Keats]

Can you fork Tera master, add the failing template as a test case and see if it works? 0.7.2 is 3 versions behind so we need to see if it still happens in the current version and whether it's a Tera bug

[junhwong]

@Keats I have tried, can determine the compile_templates! problem. But it does not have any wrong details.
The following is the test code for the test case:

    use tera::Tera;
    let mut ctx = tera::Context::new();
    //panic!("never returns!");
    let tera = compile_templates!("templates/test/*");
    tera.render("index.html.tera", &ctx);

[Keats]

What about the templates? Can you push a sample project that fails on github or gitlab?

[junhwong]

this template:

{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}{{order_id}}

[Keats]

I've added a test with a template twice bigger than this one and I don't get the error: #186

Can you checkout this branch and create a failing test case?

[junhwong]

@Keats Use cargo test is passed, but use cargo run is failed!

see test projects https://github.com/junhwong/tera_test

[Keats]

Hmm both cargo test and cargo run work for me on your repo.
What error do you get? Still thread '<unknown>' has overflowed its stack?

[Eijebong]

@junhwong Are you using windows ?

I know clippy had troubles with 64 bit windows stack being too short. https://github.com/Manishearth/rust-clippy/issues/1244 might be the same kind of issue here ?

[junhwong]

@Eijebong @Keats
Yes i use win 10 pro. but i set RUST_MIN_STACK is invalid and still thread '<unknown>' has overflowed its stack error.

try:

fn main() {
    use std::env;
    use std::thread;
    use tera::Tera;
    let child = thread::Builder::new().stack_size(2 * 1024 * 1024).spawn(move || {
        let mut ctx = tera::Context::new();
        let tera = compile_templates!("templates/*");
        tera.render("index.html", &ctx);
        println!("PASSED");
    }).unwrap();
    println!("min_stack:{:?}", env::var("RUST_MIN_STACK"));
    println!("max_cached_stacks:{:?}", env::var("RUST_CACHED_STACKS"));
    child.join().unwrap();
}

is passed, stack_size 2M is enough，results:

Finished dev [unoptimized + debuginfo] target(s) in 2.14 secs
     Running `target\debug\tera_test.exe`
min_stack:Ok("33554432")
max_cached_stacks:Err(NotPresent)
PASSED

so i still can not sure the root of the problem.
and i submit this test code to test projects https://github.com/junhwong/tera_test

[Keats]

What's your rust version? Can you post the full stacktrace of the error?

[junhwong]

@Keats rust version is last version and error only thread '<unknown>' has overflowed its stack
see rwf2/Rocket#309 for get stacktrace tries.

[Keats]

The backtrace seems to be about your panic! call: thread 'main' panicked at 'This function never returns!', src\main.rs:115
What's the backtrace if you just run https://github.com/junhwong/tera_test/blob/master/src/main.rs#L22-L27?

[junhwong]

panic! is used to test stacktrace only . results is here:rwf2/Rocket#309 (comment)

[junhwong]

If really can not find the reason, then i use test repo ways for hack to complete my works!
Well, that's only that, THX!

[Keats]

Maybe open a thread on https://reddit.com/r/rust or http://users.rust-lang.org/, I have no idea what's going on myself

[Keats]

Did you manage to figure it out? If not I'd like to post it on http://users.rust-lang.org/ since I'd like to have it fixed for everyone

[Keats]

That's weird, it seems I can reproduce it now on my machine

[junhwong]

@Keats Yes this is a strange question, i just hack it now and i also look forward to the solution to this problem.

[Keats]

I believe this is the same issue as https://stackoverflow.com/questions/28660362/thread-main-has-overflowed-its-stack-when-constructing-a-large-tree as I use VecDeque when building the AST.
I tried implementing Drop for Node but it overflows before reaching it, removing most of the VecDeque and just using Vec but the issue is still there.

(branch with failing test and some changes like using Vec instead of VecDeque in some places: https://github.com/Keats/tera/tree/overflow, cargo run --example basic to get the error)

[Keats]

This is apparently due to a bug in the parser lib Tera is using. This lib has a 1.0 coming soon that is almost a full rewrite and that should not present this issue. So in theory this should be fixed in the next 0.11 version after pest reaches 1.0

[Keats]

Fixed as of 0.11.0-beta, sorry for the delay :o