gplugin/gplugin

Make sure gtk4 was found before trying to build vala bindings against it
default tip
9 days ago, Gary Kramlich
7027845d098d
Make sure gtk4 was found before trying to build vala bindings against it

This error only showed up when gtk4 was enabled but not found.

Testing Done:
Built on haiku that doesn't have gtk without setting `-Dgtk4=false`.
Built on debian testing normally.

Reviewed at https://reviews.imfreedom.org/r/3069/
option(
'doc',
type : 'boolean', value : true, yield : true,
description : 'build documentation with gtk-doc'
)
option(
'introspection',
type : 'boolean', value : true, yield : true,
description : 'Whether or not to build a GObject Introspection type library'
)
option(
'devenv-config-dir',
type : 'string',
description : 'config directory for running a devenv (defaults to a subdirectory of buildroot)'
)
option(
'gtk4',
type : 'feature',
description : 'Whether or not to build the GTK4 library'
)
option(
'help2man',
type : 'boolean', value : true,
description : 'Whether or not to build man pages from --help output'
)
option(
'install-gplugin-gtk4-viewer',
type : 'boolean', value : true,
description : 'Whether or not to install the GTK4 viewer application'
)
option(
'install-gplugin-query',
type : 'boolean', value : true,
description : 'Whether or not to install the query application'
)
option(
'lua',
type : 'boolean', value : true,
description : 'Whether or not to build the Lua plugin loader'
)
option(
'nls',
type : 'boolean', value : true,
description : 'Install translation files'
)
option(
'python3',
type : 'boolean', value : true,
description : 'Whether or not to build the Python 3.x plugin loader'
)
option(
'vapi',
type : 'boolean', value : true,
description : 'Whether or not to build vapi files for gplugin'
)