gtk3+quartz opens no windows, any suggestions?

[René J.V. Bertin]

Hi,

GTk4 currently requires a newer OS version that I'm running so I decided to do some simple testing with GTk3+quartz. I already had a slightly customised version of the port (and port:libepoxy), so it was trivial and fast to add `libepoxy-quartz` and `gtk3-quartz` subports that hardwire the +quartz variant and install into $prefix/libexec/GTQuartz . I have too many GTk3 ports installed that I want to be able to use from a remote X11 server so the current design whereby you'd have to deactivate the +x11 builds of all relevant ports in order to use the +quartz variant of even a single port is just too cumbersome.

I get the impression that meson isn't really designed for this sort of thing (you need to prepend the subprefix to $PKG_CONFIG_PATH so the "hidden" versions of dependencies are found?!) but that aspect worked out for `port:gtk3-quartz` finding `port:libepoxy-quartz` without having to set a build conflict.

The demo applications run and with a valid event loop and skeleton toplevel menu, but they don't show a window at all and the "about" dialog only shows a titlebar. No glib error messages whatsoever.

Does this ring a bell for anyone, iow, is this a known symptom with a known cause/solution? 

FWIW, I replaced the `[variant_isset quartz]` calls with `[variant_isset:quartz]` (idem for x11), where
{{{
proc variant_isset:quartz {} {
    global subport name
    return [expr {[variant_isset quartz] || ${subport} eq "${name}-quartz"}]
}

proc variant_isset:x11 {} {
    global subport
    return [expr {[variant_exists x11] && [variant_isset x11]}]
}
}}}

so changes to the Portfile and risk of overlooking something could be minimal.

Thanks,
R.