Options handling overhaul breaks backward compatibility

[dnicolodi]

In meson-python we pass some opinionated options to meson setup to tailor the project configuration to the users expectations when building a Python package. Among other things, we pass the -Db_ndebug=if-release options. AFAIU, b_ndebug is not recognized as a valid option when project() does not specify at least one language or one is added with add_languages().

There may be good reasons for this change. However, in meson-python we want to be able to keep passing the -Db_ndebug option. Is there is a way to know before hand if it is a valid option?

Funny enough, if the project is configured without the -Db_ndebug option, and then reconfigured with it, the option is recognized as valid regardless of the project configuring a language or not.

$ meson setup build/ -Db_ndebug=if-release
The Meson build system
Version: 1.7.99
[...]

meson-python undefined

  User defined options
    b_ndebug: if-release


ERROR: Unknown options: "b_ndebug"

A full log can be found at /Users/daniele/src/meson-python/build/meson-logs/meson-log.txt
$ meson setup build/
The Meson build system
Version: 1.7.99
[...]
Found ninja-1.12.1 at /usr/local/bin/ninja
$ meson setup build/ --reconfigure -Db_ndebug=if-release
The Meson build system
Version: 1.7.99
[...]
meson-python undefined

  User defined options
    b_ndebug: if-release

Found ninja-1.12.1 at /usr/local/bin/ninja
$ 

[bonzini]

Would it be possible for you to write a unit test?

[bonzini]

Related to #12923

[jpakkane]

Does the linked MR fix this for you?

[dnicolodi]

It does. Thank you.

[dnicolodi]

I've just run into a variation of the same issue:

$ meson setup build/ -Db_ndebug=if-release
$ rm -r build/meson-private/coredata.dat
$ meson setup build/ -Db_ndebug=if-release
The Meson build system
Version: 1.7.99
[...]
  File "/Users/daniele/src/meson-python/lib/python3.11/site-packages/mesonbuild/options.py", line 1353, in initialize_from_top_level_project_call
    assert isinstance(keystr, str)
           ^^^^^^^^^^^^^^^^^^^^^^^
AssertionError

meson.build:5:0: ERROR: Unhandled python exception

    This is a Meson bug and should be reported!

This used to work as meson uses (used?) the presence of meson-private/coredata.dat as an indication of whether the build directory is initialized or not. Adding --reconfigure to the last meson invocation does not change the result. The presence of the -Db_ndebug=if-release argument is necessary to reproduce the issue.

[eli-schwartz]

Does the linked MR fix this for you?

@jpakkane note that you need to have the "closes #xxxx" on a separate line or the MR will not be linked, only the commit, and then it becomes awkward to reverse-engineer where the discussion happened.