Move-construction QTextCharFormat crashes on iOS

While working on text-highlighter for an iOS-app I discovered some odd behavior using a global QTextCharFormat object.

Basically calling a member of a QTextCharFormat and then move-construct that object into a global causes the app to crash on iOS (Works fine on Windows using MSVC)

Here is a minimal example illustrating the problem:

main.cpp

#include <QTextCharFormat>

QTextCharFormat makeKeywordFormat(const QBrush &pForeground, int pFontWeight)
{
    QTextCharFormat format;
    format.setForeground(pForeground);
    format.setFontWeight(pFontWeight);
    return format;
}

const QBrush grayBrush(Qt::gray);
const QTextCharFormat kDefaultFormat(makeKeywordFormat(grayBrush, QFont::Thin));

int main(int, char **)
{
    return 0;
}

minimal-demo.pro

QT += core
TARGET = minimal-demo
CONFIG += c++17
SOURCES += main.cpp

Observed behavior:

Only setFontWeight:

21:36:51: Starting remote process.
program received signal -111, thread:7d15b;

00:00534d0101000000;01:7800408102000000;02:6000408102000000;03:b650b08102000000;04:ff00000000000000;05:0000000000000000;06:0000000000000000;07:0000000000000000;08:0000000000000000;09:0100000000000000;0a:0800000000000000;0b:0000000000000000;0c:0100000000000000;0d:0100000000000000;0e:0300000000000000;0f:a700000000000000;10:fb07000000000000;11:0000000000000000;12:0000000000000000;13:a00adb0101000000;14:c0f5da0101000000;15:5051236f01000000;16:e00a394802000000;17:1800000000000000;18:f885bc0001000000;19:f4f4bc0001000000;1a:8812490101000000;1b:0000000000000000;1c:1085bc0001000000;1d:d04d236f01000000;1e:2436d80001000000;1f:b04d236f01000000;20:dcc4170101000000;21:00000060;metype:1;mecount:2;medata:1;medata:c;memory:0x16f234dd0=f04d236f01000000d035d80001000000;memory:0x16f234df0=204e236f010000006cdfe20001000000;

Repeated many times
hit maximum number of consecutive signals, stopping 

with setForeground

rogram received signal 6, thread:7d2bb;00:0000000000000000;01:0000000000000000;02:0000000000000000;03:0000d00901000000;04:9032d00901000000;05:0d00000000000000;06:0a00000000000000;07:3f00000000000000;08:0008000000000000;09:2068511102000000;0a:a41e511102000000;0b:ed09984c02000000;0c:ed09984c02000000;0d:1500000000000000;0e:0100000000000000;0f:8108000000000000;10:4801000000000000;11:0000000000000000;12:0000000000000000;13:0600000000000000;14:802b7b0101000000;15:50d1966f01000000;16:0303000000000000;17:602c7b0101000000;18:f805490001000000;19:c874490001000000;1a:8892d50001000000;1b:0000000000000000;1c:1005490001000000;1d:a0cd966f01000000;1e:2020511102000000;1f:70cd966f01000000;20:0461491102000000;21:00000000;metype:5;mecount:2;medata:10003;medata:6;memory:0x16f96cda0=e0cd966f0100000078dd3e1102000000;memory:0x16f96cde0=10ce966f01000000181a880001000000;
ASSERT failure in QVariant: "Trying to construct an unknown type", file kernel/qvariant.cpp, line 1421

Repeated many times

hit maximum number of consecutive signals, stopping

Neither setForeground nor setFontWeight called works.

Also moving the construction inside main works