Interestingly, I tried to compile TheIDE with a USEMALLOC flag and got a result below.

Linking...
/bin/x86_64-unknown-linux-gnu-ld: /home/xxx/dvlp/cpp/code/upp/out/Core/SSL/CLANGcpp17um.Debug.Debug_Full.Gui.Shared/Util.o: in function `__cxx_global_var_init':
/home/xxx/dvlp/cpp/code/upp/git/uppsrc/Core/Core.h:426:(.text.startup+0xc): undefined reference to `MemDiagCls::MemDiagCls()'
/bin/x86_64-unknown-linux-gnu-ld: /home/xxx/dvlp/cpp/code/upp/out/Core/SSL/CLANGcpp17um.Debug.Debug_Full.Gui.Shared/Util.o: in function `__cxx_global_var_init':
/home/xxx/dvlp/cpp/code/upp/git/uppsrc/Core/SSL/Util.cpp:(.text.startup+0x13): undefined reference to `MemDiagCls::~MemDiagCls()'
...