TL 2024 cannot be installed on some Windows computers (again!)

[Denis Bitouzé]

Unfortunately, same punishment with:

PS D:\> set TEXLIVE_PREFER_OWN=1

BTW:

PS D:\> echo %TEXLIVE_PREFER_OWN%

just returns:

%TEXLIVE_PREFER_OWN%

----- Mail original -----
> De: "Zdenek Wagner" <zdenek.wagner at gmail.com>
> À: "Bruno Voisin" <bvoisin at icloud.com>
> Cc: "Denis Bitouzé" <denis.bitouze at univ-littoral.fr>, "Bruno Voisin via tex-live" <tex-live at tug.org>
> Envoyé: Dimanche 1 Décembre 2024 11:36:58
> Objet: Re: TL 2024 cannot be installed on some Windows computers (again!)

> ne 1. 12. 2024 v 1:31 odesílatel Bruno Voisin via tex-live
> <tex-live at tug.org> napsal:
>>
>> ...
>>
>> In the TL doc, this is only mentioned about the changes for year 2019
>>
>>   https://tug.org/texlive/doc/texlive-en/texlive-en.html#x1-880009.1.16
>>   https://www.tug.org/texlive/doc/texlive-fr/texlive-fr.html#x1-9400010.1.16
>>
>> So, on Unix-style systems (I'm on the Mac myself), this would be something like
>>
>>   TEXLIVE_PREFER_OWN=1 install-tl -gui
>>
>> I don't know how to achieve the same on Windows. I checked for a mention of that
>> variable (or its effect) in the Advanced screen of the install GUI, there's
>> none.
>>
> The environment setting in Windows persist, you just type
> set TEXLIVE_PREFER_OWN=1
> 
> It will be used for all subsequent commands in the same "black
> window", you can verify it by
> echo %TEXLIVE_PREFER_OWN%
> 
> Or you can define it in user's environment in the system setting, it
> will then be used forever until the user removes it. And it will be
> used even in programs started from GUI. I am not sure whether it is
> necessary to restart Windows after such change in the system setting,
> I am not a Windows expert.
> 
>> Actually I wasn't aware of the above at all, found it the hard way by looking at
>> the code. Inside the install package, there's
>> texmf-dist/scripts/texlive/tlmgr.pl which on lines 7155 ff. delegates the task
>> of locating the executables to a setup_programs variable, writing
>>
>>   # setup the programs, for w32 we need the shipped wget/xz etc, so we
>>   # pass the location of these files to setup_programs.
>>
>> setup_programs is set in tlpkg/TeXLive/TLUtils.pm on lines 2890 ff., telling the
>> OS utilities are preferred save for tar on Windows (the tar-specific code is on
>> lines 2930 ff.).
>>
>> That's where TEXLIVE_PREFER_OWN comes in. Say the comments there:
>>
>>   If the C<$tlfirst> argument or the C<TEXLIVE_PREFER_OWN> envvar is set,
>>   prefer TL versions; else prefer system versions (except for Windows
>>   C<tar.exe>, where we always use ours).
>>
>> I don't know why the same is not done for xz as for tar (ie ensuring that the TL
>> version is used on Windows). Maybe simply the problem wasn't widely known.
>>
>> Bruno
>>
>>
> 
> Zdeněk Wagner
> https://www.zdenek-wagner.eu/

-- 
Denis