Debug.jl broken with julia commit e148584

[nfoti]

Julia seg faults when executing the statement using Debug.

Maybe it has something to do with the recent Expr change.

I have no idea how to figure out what's going on. Once this is fixed I'll issue a pull request to incorporate my context printing changes and then I'll work on the core guys to update the parser to incorporate file info.

[nfoti]

I was able to determine that the segfault occurs in the using Flow (well, when Flow is being processed in the long using list) in Debug.jl. At some point the memory address 0x0 is being accessed. I wasn't able to figure out much more though.

[toivoh]

I get the same thing with commit 3fee09fe96. Perhaps we can bisect the Julia changes to see what broke it. Though Julia has had some pretty major changes lately, I bet it's one of them... Not sure when I can dig into this.

[nfoti]

I had Debug.jl working with a commit after release-0.1. A few days later I
upgraded and it broke. I'll try to pinpoint the commit that broke it at
the very least.

On Fri, Mar 8, 2013 at 4:22 PM, toivoh notifications@github.com wrote:

I get the same thing with commit 3fee09fe96. Perhaps we can bisect the
Julia changes to see what broke it. Though Julia has had some pretty major
changes lately, I bet it's one of them... Not sure when I can dig into this.

—
Reply to this email directly or view it on GitHubhttps://github.com//issues/39#issuecomment-14646202
.

[nfoti]

Ok, I found a good commit and bad commit. I tried to bisect but ran into some build errors in the middle. The good commit is dae9629554 from March 4 and a bad commit is ede8b479ed from March 5 (both are the last commits of the day).

Hopefully this helps a bit.

[nfoti]

I'm pretty sure that commit 4be86b231a20c875787060e6045aabde1a0d127b is the problem as it's the one that introduced the code that causes the segfault.

I'm not completely sure though as I could not build the commit because of a build problem on OSX for commits around this one (including it). I was only able to verify that the segfault occurred for commit 2fabc57121cc45739c0fcf0ea67ccaee84c5f17c which fixed the OSX build problem. However, I suspect this is a deeper problem as the bug was fixed later that day (March 4) and then broken again the next day. I'm going to post this to julia-dev to put it on the radar that using statements are causing segfaults.

[toivoh]

You're right! I was able to build both JuliaLang/julia@4be86b2 (which segfaults) and the one before it (which doesn't). Thanks, this will be a big help in trying to sort this out! I'll see when I can dig into it more...

[nfoti]

Great! I think I'm going to be out of commission for a while finishing my thesis. Hopefully when I emerge Debug.jl will be working on julia 0.2.

Also, I submitted a pull request to the release-0.1 branch for my updates to the parser that give all source lines file information, however, there hasn't been much activity. If you wanted to try to convince the core people to accept it or to figure out a better way to include the information (as you have more clout in the community) that would go a long way toward giving people a really useful debugging experience and could convince a lot of people to switch to julia for their research code and data analysis.

Thanks.

[toivoh]

I hope so too! I'll see what I can do.
Good luck with your thesis, and thanks for all your help!

[toivoh]

I managed to the segfault down to a really short example, posted as JuliaLang/julia#2560.
It seems that I can fix it by moving the exports in Debug.jl to after the using statements. But when I did that, another insidious error surfaced. If I can get that sorted, I will update the package.

[nfoti]

I saw that Jeff fixed the segfault already. I'm still running into
problems using Debug.jl, but at least they're julia errors. Now we just
need the parser update to be pulled into the source.

If you let me know when you have the Debug.jl package working with
julia-0.2 again I will issue a pull request for my parser change on master
(right now the pull-requiest is only for release-0.1).

Thanks.

On Wed, Mar 13, 2013 at 4:59 PM, toivoh notifications@github.com wrote:

I managed to the segfault down to a really short example, posted as
JuliaLang/julia#2560 JuliaLang/julia#2560.
It seems that I can fix it by moving the exports in Debug.jl to after the
using statements. But when I did that, another insidious error surfaced.
If I can get that sorted, I will update the package.

—
Reply to this email directly or view it on GitHubhttps://github.com//issues/39#issuecomment-14868100
.

[doobwa]

Are there any updates on getting Debug.jl working on julia-0.2? More specifically, I am not sure how the using calls will need to change once the commit for JuliaLang/julia#2375 gets pulled into master. I was able to get rid of a few errors by always doing using Debug.AST rather than using AST, but is that the right way to do it?

[JeffBezanson]

To use your own submodules, you will need to write using .AST etc.

[toivoh]

It seems to be working now.