Debug Error,qstringview.h Line:179,ASSERT:"len>=0" in file

[fredmarks]

My .exe sometime take this Debug Error and stop running. No everytime.How to solve it?

[JonB]

@fredmarks
Your code is doing something wrong with a string. If this happens on a development machine with VS installed, do as it says at the end, click Retry, it should take you into debugger at the fault, look in the stack view pane to see where in your code it was called from.

Otherwise you can try/hope it goes wrong when you repeatedly run it under debugger.

There is no "magic wand" for errors which are "No everytime". It might stem from an uninitialized variable which shows up in different ways, or in certain circumstances.

If I had to guess the ASSERT comes from the line at https://codebrowser.dev/qt5/qtbase/src/corelib/text/qstringview.h.html#175

    Q_DECL_CONSTEXPR QStringView(const Char *str, qsizetype len)
        : m_size((Q_ASSERT(len >= 0), Q_ASSERT(str || !len), len)),

A QStringView is being created from a const Char * where the passed-in len is negative. Qt may be calling this indirectly from other code, but if you do create QStringViews look at that.