I'm using an old version of Qt creator (3.1.2) and mingw32 (mingw482_32) on Windows 10 (home).
I created a sub-projects project, for the sake of being able to reuse some of the components.
One of my subprojects is designed to generate a static library, called libparam which I use in my main application.
The trouble is that when I modify some of the code in libparam and I build libparam again and call my application, it very clearly uses old debug information.
For example, I have a function set_name(char *s, int size). I added a local variable called tmp, and compiled with that. At some point later I remove the temporary variable, but the debugger still shows it up as being one of my local variables.
When I change some of my manifest constants it is clear that the old version is used. This ghost copy still exists even if I rebuild libparam or if I delete the debug-mode objects entirely in their debug directory.
Strangely it is most likely to update the debug info if I update the header file of libparam, which, by the way is explicitly mentioned in subproject of the main application.
It's as if something is being cached, but invisibly.
I do have a tool called Search Everything, and when I search for libparam.a I see it has lots of versions stashed away for example in
C:\Users\feraudyh\AppData\Local\Microsoft\Windows\ FileHistory\Data\5194\D\devt\FeraudyQt\Surfaces\bu ild-Surfaces-Desktop_Qt_5_3_MinGW_32bit-Debug\Libparam\debug\libLibParam.a
C:\Users\feraudyh\AppData\Local\Microsoft\Windows\ FileHistory\Data\5195\D\devt\FeraudyQt\Surfaces\bu ild-Surfaces-Desktop_Qt_5_3_MinGW_32bit-Debug\Libparam\debug\libLibParam.a
(and a few more)

Could this be the evidence of the presence of hidden copies???
Any suggestions?
Thank you for your attention.