(Why) Does ./sage -br use Meson?

[Gareth Ma]

Hi all, I have been asked this by another Sage developer, which is whether ./sage -b or ./sage -br use Meson. The command actually fails for me initially on Arch Linux, as ./configure or using make is now "not recommended" and errors out. After running ./configure --disable-meson-check, I noticed that the build process runs `meson setup ...`. This was interesting as it never ran `meson compile` afterwards, and it shouldn't since it's using the old make/autoconf build system. So my question: how is Meson used in the Sage build system?

Best regards,

Gareth

[Dima Pasechnik]

these are obsolete options, we are deprecating them now.

sage -br is now equivalent to running ./sage,
as meson takes care of rebuilding cython if needed, by running ninja in the correct directory.

sage -b has been semi-broken for long time.
And it is equivalent to running ninja.

This is being taken care of in
<https://github.com/sagemath/sage/pull/41174>

[Dima Pasechnik]

meson, or meson-python to be precise, is the backend used to build sagelib since Sage 10.7.

The whole sage "distro" is still built using autotools, this has not been changed.