[bug#60240] [PATCH v2] gnu: Add python-3.12 and python-next.

[Tanguy LE CARROUR]

Hi Lars,


Quoting Lars-Dominik Braun (2024-03-02 10:59:23)
> And actually one more nitpick: The name of the package should be
> “python-next” not “python”, otherwise `guix install python`
> will pick Python 3.12 (it’s based on the name property, not the
> variable name).

Oh… thanks! Fixed in v3.
The package name only apply when used I input, right?
I submitted other patches where I did the same. But it’s a different matter
for Python libraries, I guess!? 🤔


> > Sorry, but I’m not sure to see what you mean!?
> > Outputs are defined for `out`, `tk` and `idle`. And I see phases to move
> > files to the outputs: `move-tk-inter` and `move-idle`.
> > 
> > What do you mean by `referenced from out`? And how would you remove such
> > a reference!
> 
> so, if you look at `guix size python@3.12`, you can see
> it lists tk and tcl. And then a `grep -Ri /gnu/store/path/to/tcl
> /gnu/store/path/to/python` reveals it’s being referenced by
> lib/python3.12/_sysconfigdata__linux_x86_64-linux-gnu.py and
> lib/python3.12/config-3.12-x86_64-linux-gnu/Makefile, which are both
> part of the default “out” output. That means TCL and TK are both
> part of the closure of the python@3.12 package, i.e. they are downloaded
> whenever you install it, making the package “bigger” in size (234.5
> MiB in total to be precise). I believe we wanted to avoid that by moving
> some parts of Python into the separate “tk” output. But apparently
> that does not work (any more).
> The attached patch (on top of yours) removes these references and shrinks
> the closure of python@3.12 to 180.6 MiB.

Oh-again! Thanks for taking the time to clarify!
I think I now see what you see:

```console
$ ./pre-inst-env guix size python-next
store item                                                       total    self
/gnu/store/g6w91736w66pszrg0bmcgwx84ahw7frd-python-next-3.12.2     180.6    
82.3  45.6%
/gnu/store/gsjczqir1wbz8p770zndrpw4rnppmxi3-glibc-2.35              40.6    
38.8  21.5%
/gnu/store/930nwsiysdvy2x5zv1sf6v7ym75z8ayk-gcc-11.3.0-lib          75.3    
34.7  19.2%
/gnu/store/69wd3pd1hd3j84xr965jj2fk2qmxn0hl-openssl-3.0.8           83.4     
8.1   4.5%
/gnu/store/bcc053jvsbspdjr17gnnd9dg85b3a0gy-ncurses-6.2.20210619    81.2     
5.9   3.3%
/gnu/store/4jakqiibsvrkv4jdw1wyl6racrwv9bkh-sqlite-3.39.3           86.0     
3.4   1.9%
/gnu/store/zzyywykw7kriln18rxqd82f0k5kidla7-bash-static-5.1.16       1.8     
1.8   1.0%
/gnu/store/lxfc2a05ysi7vlaq0m3w5wsfsy0drdlw-readline-8.1.2          82.6     
1.4   0.8%
/gnu/store/6k1yys9wqrfn4y41ic1win8gpnimncwj-xz-5.2.8                77.7     
1.4   0.8%
/gnu/store/rib9g2ig1xf3kclyl076w28parmncg4k-bash-minimal-5.1.16     41.6     
1.0   0.6%
/gnu/store/2w976k6g70gkfih9wwhalqsni209vcqz-gdbm-1.23               75.9     
0.6   0.4%
/gnu/store/pl09vk5g3cl8fxfln2hjk996pyahqk8m-bzip2-1.0.8             76.7     
0.4   0.2%
/gnu/store/fw1wywd34vh33l4dq182ds5d7jdz45j5-expat-2.5.0             75.7     
0.4   0.2%
/gnu/store/slzq3zqwj75lbrg4ly51hfhbv2vhryv5-zlib-1.2.13             75.5     
0.2   0.1%
/gnu/store/w8b0l8hk6g0fahj4fvmc4qqm3cvaxnmv-libffi-3.4.4            75.5     
0.2   0.1%
total: 180.6 MiB
```

No more Tcl/Tk, thanks! 👍
If you don’t mind, I squashed your modification in v3.


>  But I don’t know whether it has any negative side-effects (i.e.
>  packages not building any more), because I can’t build libxslt with
>  Python 3.12 due to the module “imp” having been removed in Python
>  3.12.

Mmmm… is it something that has to be fixed in `libxslt`?
More likely, it comes from `python-lxml`. Our current version is 4.9.1,
and one test file (`src/lxml/html/tests/test_html5parser.py`) depends on
`imp` for `imp.new_module`.
This has been dropped in 5.1.0.

Regards,

-- 
Tanguy