Cross file property cmake_skip_compiler_test = true causes exception

[denizzzka]

Describe the bug
Cross file property cmake_skip_compiler_test = true causes Python exception

To Reproduce
To reproduce please use same files as described in #13390 with additional cross file arm_cortex_m4_cross.ini:

[host_machine]
system = 'bare metal'
cpu_family = 'arm'
cpu = 'cortex-m4'
endian = 'little'

[binaries]
d = 'ldc2'
c = 'clang'
cpp = 'clang'
d_ld = 'lld'
c_ld = 'lld'
cpp_ld = 'lld'
ar = 'llvm-ar'
strip = 'llvm-strip'
nm = 'llvm-nm'
exe_wrapper = [
        'qemu-system-arm',
            '-machine', 'netduinoplus2',
            '-nographic',
            '-semihosting',
            '-kernel',
    ]

[properties]
skip_sanity_check = true
cmake_skip_compiler_test = true

Run:

> ~/Dev/meson/meson.py setup --cross-file arm_cortex_m4_cross.ini -Ddebug=true builddir1
The Meson build system
Version: 1.5.0.rc2
Source dir: /home/denizzz/Dev/bug_meson
Build dir: /home/denizzz/Dev/bug_meson/builddir1
Build type: cross build
Project name: test project
Project version: undefined
Cross compiler sanity tests disabled via the cross file.
C compiler for the host machine: clang (clang 18.1.7 "Debian clang version 18.1.7 (1)")
C linker for the host machine: clang ld.lld 18.1.7
C++ compiler for the host machine: clang (clang 18.1.7 "Debian clang version 18.1.7 (1)")
C++ linker for the host machine: clang ld.lld 18.1.7
D compiler for the host machine: ldc2 (llvm 1.39.0 "LDC - the LLVM D compiler (1.39.0):")
D linker for the host machine: ldc2 ld.lld 18.1.7
C compiler for the build machine: ccache cc (clang 18.1.7 "Debian clang version 18.1.7 (1)")
C linker for the build machine: cc ld.bfd 2.42
C++ compiler for the build machine: ccache c++ (clang 18.1.7 "Debian clang version 18.1.7 (1)")
C++ linker for the build machine: c++ ld.bfd 2.42
D compiler for the build machine: ldc2 (llvm 1.39.0 "LDC - the LLVM D compiler (1.39.0):")
D linker for the build machine: ldc2 ld.bfd 2.42
Build machine cpu family: x86_64
Build machine cpu: x86_64
Host machine cpu family: arm
Host machine cpu: cortex-m4
Target machine cpu family: arm
Target machine cpu: cortex-m4

Executing subproject ldc method cmake 

ldc| Found CMake: /usr/bin/cmake (3.29.6)
Traceback (most recent call last):
  File "/home/denizzz/Dev/meson/mesonbuild/mesonmain.py", line 188, in run
    return options.run_func(options)
           ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/denizzz/Dev/meson/mesonbuild/msetup.py", line 364, in run
    app.generate()
  File "/home/denizzz/Dev/meson/mesonbuild/msetup.py", line 187, in generate
    return self._generate(env, capture, vslite_ctx)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/denizzz/Dev/meson/mesonbuild/msetup.py", line 226, in _generate
    intr.run()
  File "/home/denizzz/Dev/meson/mesonbuild/interpreter/interpreter.py", line 3032, in run
    super().run()
  File "/home/denizzz/Dev/meson/mesonbuild/interpreterbase/interpreterbase.py", line 169, in run
    self.evaluate_codeblock(self.ast, start=1)
  File "/home/denizzz/Dev/meson/mesonbuild/interpreterbase/interpreterbase.py", line 195, in evaluate_codeblock
    raise e
  File "/home/denizzz/Dev/meson/mesonbuild/interpreterbase/interpreterbase.py", line 187, in evaluate_codeblock
    self.evaluate_statement(cur)
  File "/home/denizzz/Dev/meson/mesonbuild/interpreterbase/interpreterbase.py", line 205, in evaluate_statement
    self.assignment(cur)
  File "/home/denizzz/Dev/meson/mesonbuild/interpreterbase/interpreterbase.py", line 642, in assignment
    value = self.evaluate_statement(node.value)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/denizzz/Dev/meson/mesonbuild/interpreterbase/interpreterbase.py", line 207, in evaluate_statement
    return self.method_call(cur)
           ^^^^^^^^^^^^^^^^^^^^^
  File "/home/denizzz/Dev/meson/mesonbuild/interpreterbase/interpreterbase.py", line 557, in method_call
    res = obj.method_call(method_name, args, kwargs)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/denizzz/Dev/meson/mesonbuild/interpreter/interpreterobjects.py", line 854, in method_call
    ret = method(state, args, kwargs)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/denizzz/Dev/meson/mesonbuild/interpreterbase/decorators.py", line 663, in wrapped
    return f(*wrapped_args, **wrapped_kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/denizzz/Dev/meson/mesonbuild/interpreterbase/decorators.py", line 250, in wrapper
    return f(*nargs, **wrapped_kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/denizzz/Dev/meson/mesonbuild/interpreterbase/decorators.py", line 569, in wrapper
    return f(*wrapped_args, **wrapped_kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/denizzz/Dev/meson/mesonbuild/modules/cmake.py", line 429, in subproject
    subp = self.interpreter.do_subproject(dirname, kw, force_method='cmake')
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/denizzz/Dev/meson/mesonbuild/interpreter/interpreter.py", line 948, in do_subproject
    raise e
  File "/home/denizzz/Dev/meson/mesonbuild/interpreter/interpreter.py", line 936, in do_subproject
    return methods_map[method](subp_name, subdir, default_options, kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/denizzz/Dev/meson/mesonbuild/interpreter/interpreter.py", line 1022, in _do_subproject_cmake
    cm_int.initialise(cmake_options)
  File "/home/denizzz/Dev/meson/mesonbuild/cmake/interpreter.py", line 876, in initialise
    self.configure(extra_cmake_options)
  File "/home/denizzz/Dev/meson/mesonbuild/cmake/interpreter.py", line 822, in configure
    toolchain = CMakeToolchain(cmake_exe, self.env, self.for_machine, CMakeExecScope.SUBPROJECT, self.build_dir, preload_file)
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/denizzz/Dev/meson/mesonbuild/cmake/toolchain.py", line 48, in __init__
    skip_status = self.properties.get_cmake_skip_compiler_test()
                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/denizzz/Dev/meson/mesonbuild/envconfig.py", line 214, in get_cmake_skip_compiler_test
    assert isinstance(raw, str)
           ^^^^^^^^^^^^^^^^^^^^
AssertionError

meson.build:7:12: ERROR: Unhandled python exception

    This is a Meson bug and should be reported!

Expected behavior
Run without error

system parameters

• Is this a cross build or just a plain native build (for the same computer)?

Cross-compilation

• what operating system (e.g. MacOS Catalina, Windows 10, CentOS 8.0, Ubuntu 18.04, etc.)

Debian Linux

• what Python version are you using e.g. 3.8.0

3.12.4

• what meson --version

~master and 1.4.1

[dcbaker]

That assert is just bogus. It should either be removed, or the code should be refactored so that a non-string ends up in common error condition.