Bug 278396

Running `nextpnr-ice40 --gui` (with the GUI enabled) results in a crash during startup with SIGSEGV.

(Running nextpnr-ice40 in bulk, non-GUI mode is not affected).

running -latest packages for this ABI

> uname -a
FreeBSD atropos 14.0-RELEASE-p5 FreeBSD 14.0-RELEASE-p5 #0: Tue Feb 13 23:37:36 UTC 2024     root@amd64-builder.daemonology.net:/usr/obj/usr/src/amd64.amd64/sys/GENERIC amd64
> pkg info -x nextpnr
nextpnr-0.7,1

Steps to reproduce:

1. Install nextpnr
2. Run `nextpnr-ice40 --gui`

Backtrace:

(gdb) bt
#0  0x000000083ce2bb37 in QMetaObject::className() const () from /usr/local/lib/qt5/libQt5Core.so.5
#1  0x000000083a4968bb in QApplication::font(QWidget const*) () from /usr/local/lib/qt5/libQt5Widgets.so.5
#2  0x000000083a4d353e in QWidget::event(QEvent*) () from /usr/local/lib/qt5/libQt5Widgets.so.5
#3  0x000000083a499b43 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/local/lib/qt5/libQt5Widgets.so.5
#4  0x000000083a49aeee in QApplication::notify(QObject*, QEvent*) () from /usr/local/lib/qt5/libQt5Widgets.so.5
#5  0x000000000e122de9 in nextpnr_ice40::Application::notify(QObject*, QEvent*) ()
#6  0x000000083ce24c21 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () from /usr/local/lib/qt5/libQt5Core.so.5
#7  0x000000083a4c6c9b in QWidget::ensurePolished() const () from /usr/local/lib/qt5/libQt5Widgets.so.5
#8  0x000000083a4d2b59 in QWidgetPrivate::setVisible(bool) () from /usr/local/lib/qt5/libQt5Widgets.so.5
#9  0x000000000e12e34f in nextpnr_ice40::DesignWidget::DesignWidget(QWidget*) ()
#10 0x000000000e12316c in nextpnr_ice40::BaseMainWindow::BaseMainWindow(std::__1::unique_ptr<nextpnr_ice40::Context, std::__1::defa
ult_delete<nextpnr_ice40::Context> >, nextpnr_ice40::CommandHandler*, QWidget*) ()
#11 0x000000000e15c8f2 in nextpnr_ice40::MainWindow::MainWindow(std::__1::unique_ptr<nextpnr_ice40::Context, std::__1::default_dele
te<nextpnr_ice40::Context> >, nextpnr_ice40::CommandHandler*, QWidget*) ()
#12 0x000000000df02724 in nextpnr_ice40::CommandHandler::executeMain(std::__1::unique_ptr<nextpnr_ice40::Context, std::__1::default
_delete<nextpnr_ice40::Context> >) ()
#13 0x000000000df04d16 in nextpnr_ice40::CommandHandler::exec() ()
#14 0x000000000e10560e in main ()