[pkg-lua-devel] Bug#781728: Bug#781728: Lua 5.2 compat

Sat Dec 20 09:23:28 GMT 2025

Hi,

On 12/19/25 15:18, Xiyue Deng wrote:
> Hi Ondřej, Jérémy,
>
> Jérémy Lal <kapouer at melix.org> writes:
>
>> Also (sorry for the top-post mode), since it is in experimental,
>> checking this page will help (wait a day or two to  see it populated)
>> https://qa.debian.org/excuses.php?experimental=1&package=luajit
>>
> +1
>
>> Le ven. 19 déc. 2025 à 12:37, Ondřej Surý <ondrej at sury.org> a écrit :
>>
>>> Sure, go ahead. I just didn’t know that this exists.
>>> --
>>> Ondřej Surý (He/Him)
>>>
>>> On 19. 12. 2025, at 12:36, Jérémy Lal <kapouer at melix.org> wrote:
>>>
>>> 
>>> Any reason to not use
>>>
>>> https://salsa.debian.org/salsa-ci-team/pipeline#enable-build-reverse-dependencies
>>>
>>> ?
>>> I can do it if needed.
>>>
> Thanks!  I was trying to set up ratt but I guess this will work better.
>
>>> Le ven. 19 déc. 2025 à 09:37, Ondřej Surý <ondrej at sury.org> a écrit :
>>>
>>>> As I had couple of spare cycles, the updated package is now in
>>>> experimental.
>>>>
>>>> I don't have the time to test all the downstream dependencies, so I would
>>>> appreciate if you can walk through all the packages that Build-Depend or
>>>> Depend on luajit and test whether everything works as expected.
>>>>
> Thanks very much for your reply and working on this!  Really appreciate it!
>
> Another question: I don't seem to find your changes on Salsa.  Are they
> pushed?
>
>>>> If you send me your salsa login, I can add you as a co-maintainer of the
>>>> luajit package.
>>>>
> My Salsa login: https://salsa.debian.org/manphiz.
>
> I guess once everything is pushed I can help enable Salsa CI with reverse
> dependency checking, unless you or Jérémy beats me to it :)
>
> @amarti: Aniol, I can also help test Aegisub with the updated LuaJIT if
> you are OK to add me as co-maintainer.  Thanks in advance!

I'm currently very busy so this would be great. I've just added you as a 
maintainer in Salsa.

Thanks!

>
>>>> (I'm not subscribed to d-d).
>>>>
>>>> Ondrej
>>>> --
>>>> Ondřej Surý (He/Him)
>>>> ondrej at sury.org
>>>>
>>>>> On 19. 12. 2025, at 8:37, Xiyue Deng <manphiz at gmail.com> wrote:
>>>>>
>>>>> I'm now CCing debian-devel at .  Please excuse the top posting where I
>>>>> explain the status quo and seek for advice.
>>>>>
>>>>> Bug#781728 is about enabling Lua 5.2 compatible mode in LuaJIT, which
>>>>> has been supported for at least 13 years (see the last commit touching
>>>>> the macro definition at [1]).  The main client using this is Aegisub
>>>>> which since 3.4.2 requires LuaJIT to enable 5.2 compatible mode.
>>>>> Currently Aegisub embeds its own LuaJIT so as to enable this, but as the
>>>>> embedded official LuaJIT doesn't support some of the release archs
>>>>> e.g. ppc64el, riscv64, and s390x.  The LuaJIT in Debian supports riscv64
>>>>> and s390x and can support ppc64el in newer versions.  I have filed
>>>>> Bug#1116248 to Aegisub for tracking.  It would be great if the LuaJIT in
>>>>> Debian can just enable this so that Aegisub does not need to embed it.
>>>>> (Also CCing the Aegisub maintainer just in case.)
>>>>>
>>>>> There may be concerns on binary compatibility on enabling Lua 5.2
>>>>> compatibility mode.  I'm not an expert on library API/ABI compatibility,
>>>>> though I have done some rudimentary analysis based on library symbols,
>>>>> e.g. output of `nm -D' of libluajit-5.1.so.2.1.1737090214 from
>>>>> libluajit-5.1-2 package, and besides symbol addresses there is no diff
>>>>> (please see the nm-luajit-unpatched.txt, nm-luajit-patched.txt for the
>>>>> symbols before and after applying the patch, and
>>>>> nm-luajit-unpatched-vs-patched.diff for the diff).  I think this should
>>>>> suggest that it is a safe change, and even if it is not, a transition
>>>>> should be sufficient to resolve any incompatibility.
>>>>>
>>>>> The reason for including debian-devel@ in the discussion is that there
>>>>> has been no reply from the Lua maintainers or package uploaders since.
>>>>> I'd like to first state that this email has no ill-intention, as people
>>>>> may be busy due to life, work, etc. so it's totally understandable.  I
>>>>> would just like to try to move things forward.  Of course, if the Lua
>>>>> maintainers or uploaders would like to provide any guidance it would
>>>>> still be welcome.  But in case there is none, I wonder what would be the
>>>>> best way to proceed?  As currently I don't claim that I have the
>>>>> required specialty to be an uploader, would a NMU be acceptable (and
>>>>> commit to Salsa so that this doesn't get lost)?  As a DM, I would still
>>>>> need a sponsor if this is the way forward.
>>>>>
>>>>> Thanks in advance!  And any advice (or suggestion to better handle this
>>>>> situation) would be appreciated.
>>>>>
>>>>> (Please also see below for previous communications on this bug.)
>>>>>
>>>>> Xiyue Deng <manphiz at gmail.com> writes:
>>>>>
>>>>>> Xiyue Deng <manphiz at gmail.com> writes:
>>>>>>
>>>>>>> (CCing the package uploaders.)
>>>>>>>
>>>>>>> Xiyue Deng <manphiz at gmail.com> writes:
>>>>>>>
>>>>>>>> Xiyue Deng <manphiz at gmail.com> writes:
>>>>>>>>
>>>>>>>>> On Fri, 27 Dec 2024 13:08:17 +0100 =?UTF-8?Q?Aniol_Mart=C3=AD?=
>>>>>>>>> <aniol.marti at riseup.net> wrote:
>>>>>>>>>> Dear Maintainer,
>>>>>>>>>>
>>>>>>>>>> i am the maintainer of Aegisub. Version 3.4.0 was recently
>>>> released but
>>>>>>>>>> it requires LuaJIT with Lua 5.2 compat. Are there any plans about
>>>>>>>>>> supporting it?
>>>>>>>>>>
>>>>>>>>>> We are currently discussing it in
>>>>>>>>>> https://github.com/TypesettingTools/Aegisub/issues/239. One
>>>> option that
>>>>>>>>>> I'm considering is bundling LuaJIT with Aegisub, but the Debian
>>>> Policy
>>>>>>>>>> encourages not doing that. Do you know if there are any other
>>>> packages
>>>>>>>>>> in a similar situation?
>>>>>>>>>>
>>>>>>>>>> Aniol
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>> As David mentioned in [1], this should be as simple as adding
>>>>>>>>> "-DLUAJIT_ENABLE_LUA52COMPAT" to CFLAGS and it should be ABI/API
>>>>>>>>> compatible.  Please consider adding this support so that Aegisub
>>>> and
>>>>>>>>> other packages can use it directly.
>>>>>>>>>
>>>>>>>>> [1] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=781728#16
>>>>>>>>>
>>>>>>>>> --
>>>>>>>>> Xiyue Deng
>>>>>>>> I have tested adding the flags and the result is promising: aegisub
>>>> can
>>>>>>>> now directly build against libluajit-5.1-dev built with the flags and
>>>>>>>> works well.
>>>>>>>>
>>>>>>>> I have created a MR on Salsa[1] and hope it can be reviewed and
>>>> merged.
>>>>>>>> [1] https://salsa.debian.org/lua-team/luajit/-/merge_requests/3
>>>>>>>>
>>>>>>> Friendly ping.  This is a blocking issue for Aegisub and currently
>>>>>>> preventing it from migrating to Forky.
>>>>>>>
>>>>>>> Though my previous claim may be wrong that enabling this flag may
>>>>>>> probably require a transition.  I would like to help analyze the
>>>>>>> situation and move this bug forward.  TIA!
>>>>>>>
>>>>>> Friendly ping.  It's concerning that we still haven't heard back from
>>>>>> the Lua team, though it's understandable that the Lua team may be busy
>>>>>> with daily life/work.  I intend to bring this topic to debian-devel@
>>>> for
>>>>>> comments next, not for pushing, but to seek for suggestions on
>>>> resolving
>>>>>> this issue.
>>>>>>
>>>>>>>> --
>>>>>>>> Regards,
>>>>>>>> Xiyue Deng
>>>>>>> --
>>>>>>> Regards,
>>>>>>> Xiyue Deng
>>>>> [1]
>>>> https://github.com/LuaJIT/LuaJIT/commit/23932a6c8b7ef434bc963139b4160b1058fa6f7f
>>>>> --
>>>>> Regards,
>>>>> Xiyue Deng
>>>>>
>>>> <nm-luajit-patched.txt><nm-luajit-unpatched.txt><nm-luajit-unpatched-vs-patched.diff>
>>>>
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