SUMMARY

Consider code like this:

---snip---
#define MY_CONSTANT(type, name, value)                \
static const type &name() {                           \
    static const type var{QLatin1String(value)};      \
return var;                                           \
}
#define MY_STRING_CONSTANT(name, value) MY_CONSTANT(QString, name, value)

MY_STRING_CONSTANT(fooProperty, "foo")
MY_STRING_CONSTANT(barProperty, "bar")
---snap---

Applying the qt6-qlatin1stringchar-to-u fixit will create duplicates in the replacements yaml file at the position of QLatin1String within the macro.
This leads to errors like this:

The new replacement overlaps with an existing replacement.
New replacement: ../../../../master/src/lib/corelib/tools/stringconstants.h: 2133:+20:"u"~/""
Existing replacement: ../../../../master/src/lib/corelib/tools/stringconstants.h: 2133:+20:"u"*""


ADDITIONAL INFORMATION

Playground project for this was https://code.qt.io/cgit/qbs/qbs.git/
and the file I ran the fixit on was src/lib/corelib/language/language.cpp