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

Fri Dec 19 14:23:18 GMT 2025

Le ven. 19 déc. 2025 à 15:19, Xiyue Deng <manphiz at gmail.com> a écrit :

> 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 :)
>

Mind that it shouldn't be enabled by default, as explained in salsa-ci's
readme linked above,
one must do a git push -o xxxx.

>
> @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 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>
> >>>
> >>> _______________________________________________
> >>> pkg-lua-devel mailing list
> >>> pkg-lua-devel at alioth-lists.debian.net
> >>> https://alioth-lists.debian.net/cgi-bin/mailman/listinfo/pkg-lua-devel
> >>>
> >>
>
> --
> Regards,
> Xiyue Deng
>