glib fails to configure with KeyError: Tried to access nonexistant project parent option b_vscrt.

[tp-m]

Option refactor regression I presume.

$ git clone https://gitlab.gnome.org/GNOME/glib.git

$ cd glib

$ ~/Devel/meson/meson.py setup b
The Meson build system
Version: 1.7.99
Source dir: /tmp/glib
Build dir: /tmp/glib/b
Build type: native build
Project name: glib
Project version: 2.83.3
C compiler for the host machine: ccache cc (gcc 14.2.0 "cc (Debian 14.2.0-14) 14.2.0")
C linker for the host machine: cc ld.bfd 2.43.90.20250122
Host machine cpu family: x86_64
Host machine cpu: x86_64
Compiler for C supports arguments -std=c89: YES 
Compiler for C supports arguments -std=c99: YES 
Compiler for C supports arguments -std=c11: YES 
Compiler for C supports arguments -std=c17: YES 
C++ compiler for the host machine: ccache c++ (gcc 14.2.0 "c++ (Debian 14.2.0-14) 14.2.0")
C++ linker for the host machine: c++ ld.bfd 2.43.90.20250122
Compiler for C++ supports arguments -std=c++98: YES 
Compiler for C++ supports arguments -std=c++03: YES 
Compiler for C++ supports arguments -std=c++11: YES 
Compiler for C++ supports arguments -std=c++14: YES 
Compiler for C++ supports arguments -std=c++17: YES 
Compiler for C++ supports arguments -std=c++20: YES 
Compiler for C++ supports arguments -std=c++2b: YES 
Compiler for C++ supports arguments -std=c++latest: NO 
Checking if "building for musl libc" compiles: NO 
Program ./.gitlab-ci/thorough-test-wrapper.sh found: YES (/bin/bash /tmp/glib/./.gitlab-ci/thorough-test-wrapper.sh)
Program valgrind found: YES (/usr/bin/valgrind)
Compiler for C supports arguments -fno-strict-aliasing: YES 
Traceback (most recent call last):
  File "/home/tpm/Devel/meson/mesonbuild/mesonmain.py", line 193, in run
    return options.run_func(options)
           ~~~~~~~~~~~~~~~~^^^^^^^^^
  File "/home/tpm/Devel/meson/mesonbuild/msetup.py", line 407, in run
    app.generate()
    ~~~~~~~~~~~~^^
  File "/home/tpm/Devel/meson/mesonbuild/msetup.py", line 189, in generate
    return self._generate(env, capture, vslite_ctx)
           ~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/tpm/Devel/meson/mesonbuild/msetup.py", line 266, in _generate
    intr.run()
    ~~~~~~~~^^
  File "/home/tpm/Devel/meson/mesonbuild/interpreter/interpreter.py", line 3061, in run
    super().run()
    ~~~~~~~~~~~^^
  File "/home/tpm/Devel/meson/mesonbuild/interpreterbase/interpreterbase.py", line 169, in run
    self.evaluate_codeblock(self.ast, start=1)
    ~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^
  File "/home/tpm/Devel/meson/mesonbuild/interpreterbase/interpreterbase.py", line 194, in evaluate_codeblock
    raise e
  File "/home/tpm/Devel/meson/mesonbuild/interpreterbase/interpreterbase.py", line 186, in evaluate_codeblock
    self.evaluate_statement(cur)
    ~~~~~~~~~~~~~~~~~~~~~~~^^^^^
  File "/home/tpm/Devel/meson/mesonbuild/interpreterbase/interpreterbase.py", line 204, in evaluate_statement
    self.assignment(cur)
    ~~~~~~~~~~~~~~~^^^^^
  File "/home/tpm/Devel/meson/mesonbuild/interpreterbase/interpreterbase.py", line 641, in assignment
    value = self.evaluate_statement(node.value)
  File "/home/tpm/Devel/meson/mesonbuild/interpreterbase/interpreterbase.py", line 200, in evaluate_statement
    return self.function_call(cur)
           ~~~~~~~~~~~~~~~~~~^^^^^
  File "/home/tpm/Devel/meson/mesonbuild/interpreterbase/interpreterbase.py", line 527, in function_call
    res = func(node, func_args, kwargs)
  File "/home/tpm/Devel/meson/mesonbuild/interpreterbase/decorators.py", line 237, in wrapper
    return f(*nargs, **wrapped_kwargs)
  File "/home/tpm/Devel/meson/mesonbuild/interpreterbase/decorators.py", line 62, in wrapped
    return f(*wrapped_args, **wrapped_kwargs)
  File "/home/tpm/Devel/meson/mesonbuild/interpreter/interpreter.py", line 1083, in func_get_option
    value_object, value = self.coredata.optstore.get_option_from_meson_file(options.OptionKey(optname, self.subproject))
                          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/tpm/Devel/meson/mesonbuild/options.py", line 1101, in get_option_from_meson_file
    (value_object, value) = self.get_value_object_and_value_for(key)
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^
  File "/home/tpm/Devel/meson/mesonbuild/options.py", line 832, in get_value_object_and_value_for
    vobject = self.get_value_object_for(key)
  File "/home/tpm/Devel/meson/mesonbuild/options.py", line 826, in get_value_object_for
    raise KeyError(f'Tried to access nonexistant project parent option {parent_key}.')
KeyError: 'Tried to access nonexistant project parent option b_vscrt.'

meson.build:365:13: ERROR: Unhandled python exception

    This is a Meson bug and should be reported!

[jpakkane]

That is caused by this line in the main meson.build

vs_crt_opt = get_option('b_vscrt')

It is unconditionally asking for that option, even though it is only defined on Windows platforms. I checked version 1.7.0 and meson configure does not list b_vscrt at all. To be fair I have no idea how this could possibly have worked before.

[tp-m]

That is caused by this line in the main meson.build

vs_crt_opt = get_option('b_vscrt')

It is unconditionally asking for that option, even though it is only defined on Windows platforms. I checked version 1.7.0 and meson configure does not list b_vscrt at all. To be fair I have no idea how this could possibly have worked before.

In 1.6.1 it returns from_buildtype which is documented as the default value.

The documentation says

The following options are available. Note that they may not be available on all platforms or with all compilers:

but does not say for each option on which platforms and with which compilers they might be available.

I am not sure if it's really reasonable to expect Meson users to just "know" what's what in this case, especially if a reasonable default value is available that was returned on Linux/with gcc before.

If it's not too much hassle we should probably add a column to the documentation with more info for each option and make this work with a warning for another release or three?

[dcbaker]

Checking for this would be so tedious, it’s not just a question of “what is my platform”, but what are both my host and build compilers, since either of them could be msvc and enable this.

[dcbaker]

If we really want to not populate these in meson 2.0 we could move to a fallback parameter, and of the fallback isn’t provided then it errors, but that’s still a breaking change and would have to go through a proper deprecation cycle