The build from sources fails when building qtbase of Qt 6.2.0 with MSVC 2019 v16.11.4 in c++20 mode on Windows.

When configuring the build of qtbase with:

configure -c++std c++20

The build fails in: 

qtbase\src\corelib\text\qregularexpression.cpp

Line: 1188

With error: error C2101: '&' on constant

Snippet of the source code:

constexpr char16_t dummySubject = 0;    
const char16_t * const subjectUtf16 = [&]()    
{        
const auto subjectUtf16 = priv->subject.utf16();        
if (subjectUtf16)
return subjectUtf16;
Q_ASSERT(subjectLength == 0);
return &dummySubject;    }();

Returning address of dummySubject in lambda function causes the build to fail when the dummySubject is constexpr, removing constexpr solves the issue.

Issue does not reproduce with:
/std:c++17

The issue is not evident in minGW nor GCC either.

Please find the reproducer at:
https://godbolt.org/z/rGra7x8aT