Bug#812741: neovim: Please don't build-depend on luajit on unsupported architectures

[John Paul Adrian Glaubitz]

On 02/23/2016 01:27 PM, James McCoy wrote:
>> Yes, but that does not mean we should accept that in Debian. Debian
>> specifically aims to provide a universal distribution which runs
>> on a large number of different targets and everyone should therefore
>> help to keep their own packages available on all targets.
> 
> So why aren't you campaigning to make LuaJIT available on all
> architectures/kernels instead of rallying against a project that wants
> to use some LuaJIT-specific functionality.  That would be more
> beneficial for everyone.

Because porting LuaJIT - or any JIT FWIW - to a new architecture is a
non-trivial task as it involves generating native code for that
architecture. That's also the reason why LLVM is not natively supported
on all of Debian's architectures yet.

>> So, you would say that ARM64, PPC64EL (POWER8), S390X, MIPS64EL and
>> SPARC64 [1] are all "arcane" and "mostly unused" architectures?
> 
> I was using it more as a comparison of goals rather than a reflection on
> what Debian currently supports.  Up until recently, Vim was still
> carrying code for Amiga, 16-bit Windows, etc.

No one was talking about AmigaOS, 16-Bit-Windows or any of that. I was
talking about *current* architectures.

> NeoVIM dropped support for a lot of legacy code and removed a lot of code
> where they could instead leverage other libraries (like libuv). This
> has meant a reduction in supported platforms, but it has also meant less
> code that has to be maintained by NeoVIM.

I understand that and I'm not saying that it's a bad decision in
general. I was all for systemd from the very start, even if it
meant making support for non-Linux kernels harder. In this case,
the benefits outlasted the disadvantages by far.

> To answer your question, though, yes those are arcane/mostly unused for
> the average desktop user.  That's part of being a Universal OS.  We
> support a lot more than just what desktop users need.  That doesn't mean
> everything has to work on all those architectures.

Those architectures are just *new*. MIPS64EL was just added during
last DebConf in Heidelberg and ARM64/PPC64EL aren't so old either. It's
natural they don't have a large install base yet. But it's very much
out of the question that particularly ARM64 is a *must-support*
architecture these days. I'm pretty sure the next incarnation of the
Raspberry Pi is going to be ARM64 and I'm pretty sure, there will
be people filing NeoVIM bug reports with "Why can't I use NeoVIM
on ARM64?".

> It's also not my job to make the software work on all the architectures
> where it currently doesn't or to convince upstream that they need to
> take on the extra burden of supporting architectures they're not
> strictly interested in.

Well, I think that everyone should do their best to get their packages
work on all architectures. It's simply not feasible for the porters
alone to achieve that. We need the help of all of Debian to achieve
that goal to make Debian available on any platform people are interested
in. Again, ARM64 might not be popular as of now, but it will be
very popular in the future, so we should be ready :).

> I've talked with upstream and will work on a patch to use Lua if LuaJIT
> isn't available, with the caveat that not all testing will be able to
> run where we have to fallback to Lua.  However, depending on the outcome
> of the efforts I referenced earlier, this may not be a long term
> solution.

Sounds very good, thanks.

> It would be much better to get projects like LuaJIT and libuv working on
> more platforms.

Of course, that would be better. I think this is a part were we're not
disagreeing at all. It's just not very easy to achieve that. IBM, for
example, has issued a bounty on Bountysource.com [1] for that matter
which still has not been successfully been claimed.

Adrian

> [1] https://www.bountysource.com/issues/25924774-add-ppc64le-port

-- 
 .''`.  John Paul Adrian Glaubitz
: :' :  Debian Developer - glaubitz at debian.org
`. `'   Freie Universitaet Berlin - glaubitz at physik.fu-berlin.de
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