[tex-live] t;18 pretest init

[Mojca Miklavec]

On 18 April 2017 at 12:04, Maïeul wrote:
> Le 18.04.17 à 02:17, Richard M. Koch a écrit :
>
>> Folks,
>>
>> The tlpretest site now has mactex-2017.pkg and mactex-basictex-2017.pkg.
>>
>> Note that our support policy has changed. MacTeX now supports the last
>> three
>> versions of macOS, exactly the operating systems for which Apple releases
>> security patches. So mactex-2017 and basictex-2017 require Yosemite,
>> El Capitan, or Sierra.
>>
>> The TeX Live install script has legacy binaries for older versions of
>> macOS, supplied by Mojca Miklavec.
>
> Should not be possible to maintain compatibility with older version?

There still *IS* compatibility.

We have binaries available for versions down to Mac OS X 10.5, so you
can easily install TeX Live on an older machine and it should work out
of the box (the installer is slightly broken today, but it should be
fixed by tomorrow), even though i386 and ppc might disappear next year
due to the pressure of C++11 standard that's not really supported in
the shipped libstdc++ from 2009 and earlier.

And in fact, if you are still using one of the ancient platforms, we
would be enormously grateful for testing (in particular on 10.5 ppc
and i386).

> Is there a technical reason to break compatibility?

Yes and no. It's mostly due to heavy workload to make sure that
binaries compile, install and work properly on:

- 10.5/ppc
- 10.5/i386
- 10.6/i386
- 10.6/x86_64
- 10.7
- 10.8
- 10.9
- 10.10
- 10.11
- 10.12

The installation in fact used to be tested on *every single one of
them*!!!! Now imagine stacking 10 pieces of hardware and installing a
4 GB file on each and every one of them. And whenever there was an
update or a problem, repeat the process, clean up everything and go
from scratch again.

Add to the fact Apple's policy of constantly changing their APIs, so
that two or even three compatibility versions of each GUI app had to
be provided. Plus compiled for ppc, i386, on multiple OS versions,
with different versions of Xcode each, with almost each GUI app having
its own compatibility matrix. And Apple changing their installer and
security policy each year.

You still have all the latest and greatest TeX Live binaries for older
platforms, you just loose the "one click to install that 4 GB dmg". If
you need GUIs, you can install an older MacTeX or fetch them. If you
are on an ancient platform, there's a good chance that those GUIs are
no longer receiving any updates anyway.

The other aspect is that users should be encouraged to use a supported
system if they want a smooth user experience which is why 10.10 has
been deliberately chosen (even if there was potentially no technical
reason not to start at 10.9).

That said, we would welcome any effort to help writing a simple GUI
installer for Mac (for example in Tcl/Tk or Python/Tk) and bundle it
as an app.

Mojca