Let's say i attach to process 5400 using gdb.exe -pid 5400. When i try to save core dump using gcore or gcore nameoffile into file, i'm getting an error that says warning: cannot close "core.5400": Invalid operation in cmd. I tried different versions and tried to attach to other programs but same error.
My PC is running Windows 10 x64. I'm using pre-build gdb for Windows http://www.equation.com/servlet/equation.cmd?fa=gdb