regression on -current with gtkmm3

a new victim of meson-0.60.0

gtkmm3 doesn't build anymore on -current
----------------------------------
Program python3 found: YES (/usr/bin/python3)
Found pkg-config: /usr/bin/pkg-config (0.29.2)
Run-time dependency gtk+-3.0 found: YES 3.24.30
Run-time dependency cairomm-1.0 found: YES 1.12.2
Run-time dependency pangomm-1.4 found: YES 2.42.2
Run-time dependency gdk-pixbuf-2.0 found: YES 2.42.6
Run-time dependency atkmm-1.6 found: YES 2.28.2
Run-time dependency epoxy found: YES 1.5.9
Run-time dependency glibmm-2.4 found: YES 2.64.5
Run-time dependency giomm-2.4 found: YES 2.64.5
Run-time dependency gtk+-unix-print-3.0 found: YES 3.24.30
Program mm-common-get found: NO
Program m4 found: YES (/usr/bin/m4)
Program perl found: YES (/usr/bin/perl)
Program doxygen found: YES (/usr/bin/doxygen)
Program dot found: NO
Program xsltproc found: YES (/usr/bin/xsltproc)
Compiler for C++ supports arguments -Wall: YES
../meson.build:331: WARNING: Consider using the built-in warning_level option instead of using "-Wall".
Library glibmm_generate_extra_defs-2.4 found: YES
Configuring gdkmm-3.0.pc using configuration
Configuring gdkmm-3.0-uninstalled.pc using configuration
Configuring gdkmmconfig.h using configuration
Configuring gdkmm.rc using configuration
Program /usr/bin/python3 found: YES (/usr/bin/python3)
Program /usr/bin/python3 found: YES (/usr/bin/python3)
Configuring gtkmm-3.0.pc using configuration
Configuring gtkmm-3.0-uninstalled.pc using configuration
Configuring gtkmmconfig.h using configuration
Configuring gtkmm.rc using configuration
Program /usr/bin/python3 found: YES (/usr/bin/python3)
Program /usr/bin/python3 found: YES (/usr/bin/python3)
Found pkg-config: /usr/bin/pkg-config (0.29.2)
Program glib-compile-resources found: YES (/usr/bin/glib-compile-resources)
Traceback (most recent call last):
File "/usr/lib64/python3.10/site-packages/mesonbuild/mesonmain.py", line 138, in run
return options.run_func(options)
File "/usr/lib64/python3.10/site-packages/mesonbuild/msetup.py", line 294, in run
app.generate()
File "/usr/lib64/python3.10/site-packages/mesonbuild/msetup.py", line 185, in generate
self._generate(env)
File "/usr/lib64/python3.10/site-packages/mesonbuild/msetup.py", line 229, in _generate
intr.run()
File "/usr/lib64/python3.10/site-packages/mesonbuild/interpreter/interpreter.py", line 2484, in run
super().run()
File "/usr/lib64/python3.10/site-packages/mesonbuild/interpreterbase/interpreterbase.py", line 150, in run
self.evaluate_codeblock(self.ast, start=1)
File "/usr/lib64/python3.10/site-packages/mesonbuild/interpreterbase/interpreterbase.py", line 175, in evaluate_codeblock
raise e
File "/usr/lib64/python3.10/site-packages/mesonbuild/interpreterbase/interpreterbase.py", line 168, in evaluate_codeblock
self.evaluate_statement(cur)
File "/usr/lib64/python3.10/site-packages/mesonbuild/interpreterbase/interpreterbase.py", line 181, in evaluate_statement
return self.function_call(cur)
File "/usr/lib64/python3.10/site-packages/mesonbuild/interpreterbase/interpreterbase.py", line 456, in function_call
res = func(node, func_args, kwargs)
File "/usr/lib64/python3.10/site-packages/mesonbuild/interpreterbase/decorators.py", line 713, in wrapped
return f(*wrapped_args, **wrapped_kwargs)
File "/usr/lib64/python3.10/site-packages/mesonbuild/interpreterbase/decorators.py", line 115, in wrapped
return f(*wrapped_args, **wrapped_kwargs)
File "/usr/lib64/python3.10/site-packages/mesonbuild/interpreterbase/decorators.py", line 276, in wrapper
return f(*nargs, **wrapped_kwargs)
File "/usr/lib64/python3.10/site-packages/mesonbuild/interpreter/interpreter.py", line 1969, in func_subdir
self.evaluate_codeblock(codeblock)
File "/usr/lib64/python3.10/site-packages/mesonbuild/interpreterbase/interpreterbase.py", line 175, in evaluate_codeblock
raise e
File "/usr/lib64/python3.10/site-packages/mesonbuild/interpreterbase/interpreterbase.py", line 168, in evaluate_codeblock
self.evaluate_statement(cur)
File "/usr/lib64/python3.10/site-packages/mesonbuild/interpreterbase/interpreterbase.py", line 191, in evaluate_statement
return self.evaluate_if(cur)
File "/usr/lib64/python3.10/site-packages/mesonbuild/interpreterbase/interpreterbase.py", line 274, in evaluate_if
self.evaluate_codeblock(i.block)
File "/usr/lib64/python3.10/site-packages/mesonbuild/interpreterbase/interpreterbase.py", line 175, in evaluate_codeblock
raise e
File "/usr/lib64/python3.10/site-packages/mesonbuild/interpreterbase/interpreterbase.py", line 168, in evaluate_codeblock
self.evaluate_statement(cur)
File "/usr/lib64/python3.10/site-packages/mesonbuild/interpreterbase/interpreterbase.py", line 183, in evaluate_statement
self.assignment(cur)
File "/usr/lib64/python3.10/site-packages/mesonbuild/interpreterbase/interpreterbase.py", line 568, in assignment
value = self.evaluate_statement(node.value)
File "/usr/lib64/python3.10/site-packages/mesonbuild/interpreterbase/interpreterbase.py", line 185, in evaluate_statement
return self.method_call(cur)
File "/usr/lib64/python3.10/site-packages/mesonbuild/interpreterbase/interpreterbase.py", line 484, in method_call
res = obj.method_call(method_name, args, kwargs)
File "/usr/lib64/python3.10/site-packages/mesonbuild/interpreter/interpreterobjects.py", line 754, in method_call
ret = method(state, args, kwargs)
File "/usr/lib64/python3.10/site-packages/mesonbuild/interpreterbase/decorators.py", line 713, in wrapped
return f(*wrapped_args, **wrapped_kwargs)
File "/usr/lib64/python3.10/site-packages/mesonbuild/interpreterbase/decorators.py", line 115, in wrapped
return f(*wrapped_args, **wrapped_kwargs)
File "/usr/lib64/python3.10/site-packages/mesonbuild/modules/gnome.py", line 292, in compile_resources
target_c = GResourceTarget(name, state.subdir, state.subproject, kwargs)
File "/usr/lib64/python3.10/site-packages/mesonbuild/modules/__init__.py", line 202, in __init__
super().__init__(name, subdir, subproject, kwargs)
File "/usr/lib64/python3.10/site-packages/mesonbuild/build.py", line 2330, in __init__
self.process_kwargs(kwargs, backend)
File "/usr/lib64/python3.10/site-packages/mesonbuild/build.py", line 2441, in process_kwargs
if isinstance(kwargs['install_dir'], list):
KeyError: 'install_dir'
----------------------------