Re: cross compile to MacOS

[Lars Holger Engelhard]

Dear Volker, Zach, Robert and List,

I've been happily contributing to MXE in the past, because we do cross
compile a lot using Qt. MacOS has always been on our list, too.
There actually was some project achievements in the past, we've been
calling it LXE. It has been discontinued because we noticed it seems
feasible, but would need a complete re-write to give it a jumping base
for others in a lack of time. Yet, this threat is encouraging to share
our experience and thoughts.

What have we done? We've identified MXE success factors. It is the basic
core environment built first, then adding the libraries like a recipe.
Reminding us of Yocto, it is a mechanism that just works and invites
plenty of people to contribute.
>From here, we've decided to give several approaches a try calling it the
core, like c++ and basic libs in MXE. We have tried a lot and what seems
to be most promising was osxcross (https://github.com/tpoechtrager/osxcross)

This actually worked in a PoC, but it is not pretty. Once you create an
osxcross core environment, we feel confident that adding the mechanisms
of MXE could create the libraries on top.



Can we contribute? Currently we are launching a new company on
autonomous boats, sucking out a lot of time. If possible, we would
contribute 2021.

Maybe it takes a little adjustment to MXE first. To make the first built
steps crystal clear being an 'environment builder', before adding more
complexity adding OSX environment. In too much complexity, people will
likely get lost - and there is one thing we want to avoid: people
getting to scared of the architecture jeopardizing the continuous
efforts of MXE.

Best regards,
   Lars


Am 22.11.2020 um 19:16 schrieb Volker Diels-Grabsch:
> Dear All,
>
> Thanks to Robert and Zack for explaining the situation so well, I
> don't have much to add here from a technical point of view.
>
> So instead let me add a more "historical" point of view: When I
> started mingw-cross-env and renamed it to "MXE", which stands for
> "M cross environment", I always had two "M"s in mind: MinGW and
> MacOSX.
>
> Moreover, I did have an actual software project (written in Qt) which
> I needed to port to Windows as well as Mac.
>
> But setting up cross compiling on Mac was so cumbersome that I only
> cross-built the Windows version on a Debian system with MXE, and
> compiled the Mac version natively.
>
> On the other hand, there have been promising approaches at that time,
> extracting stuff from the XCode packages and whatnot.  Perhaps there
> are still people out there having some (limited) success with that.
> But the amount of time to get into that stuff, and to make it working
> - this was to much time for myself at that time, and for all others
> who tried later as well.
>
> So if you think you have enough spare time and would like to break
> that nut, feel encouraged to try!  Extending MXE to MacOSX would be a
> huge achievement.  Just be warned that this might be a lot harder than
> it may seem, and that it might even turn out to be impossible to keep
> working in the long run.
>
>
> Regards,
> Volker
>
>
> Robert Heller wrote:
>> At Sat, 21 Nov 2020 14:48:16 -0500 Zach Bacon <wowzaman12@gmail.com> wrote:
>>
>>> In theory, yes it's possible but like what Robert mention, it's a 
>>> different beast than targeting windows platforms and to be honest I 
>>> don't think it would be beneficial to work on such a solution, 
>>> especially where you run into issues where you need to ensure the binary 
>>> can work and without a working macOS platform to test that sort of 
>>> thing, honestly I think a lot of compilation tests could potentially 
>>> fail because of that. At least targeting windows platforms using mxe you 
>>> have things like wine to test your binaries on.
>> A major problem (as I mentioned) is that Apple has put *special* effort into
>> making it hard to coss-build for MacOSX and hard to even run MacOSX on
>> anything other then a genuine Macintosh, both at the bare level or as a vm.
>> Apple makes money selling their hardware. They pretty much give their 
>> software
>> away, but with the gotcha: you gotta buy the hardware to actually run the
>> software.
>>
>>> On 2020-11-21 2:18 p.m., Robert Heller wrote:
>>>> At Sat, 21 Nov 2020 19:58:23 +0100 Valerio Messina <efa@iol.it> wrote:
>>>>
>>>>> hi,
>>>>> I'm using MXE with satisfaction and can generate for Win32 and 64.
>>>>>
>>>>> I want to cross compile my CLI, SDL and GTK applications for MacOS too.
>>>>> I looked around and found some cross-compiler for MacOS, but all require
>>>>> to download and install the Apple SDK (many GB), and some are not
>>>>> maintained anymore.
>>>>>
>>>>> Reading the MXE Introduction say it can cross compile for various target
>>>>> platforms, but as now seem only Win32 and Win64 are supported.
>>>>> Since CLI, SDL and GTK are natively cross-platform, and MacOS is quite
>>>>> similar to Linux (it is already supported as host), I hope no Apple SDK
>>>>> is needed.
>>>> MacOSX is layered on BSD (a variant called Darwin), which is POSIX (like
>>>> Linux).  Apple is rather protective of MacOSX, patitularly the non-free
>>>> parts.
>>>>
>>>>> Are there any chance that MXE will extended to support MacOS as target?
>>>> Highly unlikely -- MacOSX is a very different animal from Win32 and Win64. 
>>>> To
>>>> have any chance of properly supporting MacOSX, partularly the current 
>>>> version,
>>>> you will have to get an actual Mac -- most likely you option is get a 
>>>> MacMini,
>>>> which can be networked and ssh'ed into from a Linux machine (shell / CLI
>>>> access) and/or use a VNCViewer if you need to use the MacOSX GUI (eg 
>>>> testing
>>>> GTK apps). And running MacOSX in a virtual machine is a very tricky 
>>>> business
>>>> -- said to be possible, but you need to first create a virtual 
>>>> "Hackintosh",
>>>> which is somewhat non-tivial.
>>>>
>>>> The build tools for MacOSX are freely available from Apple, but they are 
>>>> only
>>>> meant to run on an actual Mac.
>>>>
>>>>> thank you for this good software,
>>>                                                                             
>>>  
>>>
>> -- 
>> Robert Heller             -- Cell: 413-658-7953 GV: 978-633-5364
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