In a command prompt I browsed to C:\MinGW\bin and ran:

mingw-get.exe install gdb

That fixed it for me. Not sure if it matters but I have C:\MinGW\bin in my path (guess I probably didn't need to browse to C:\MinGW\bin).

No idea what MinGW Installation Manager is or why you were trying to use it when you are using msys2.

To install mingw64 gdb in msys2, you really just need to:

pacman -S mingw-w64-x86_64-gdb

You should probably run pacman -Syu twice before you run the above though.

As you can see, if you need other mingw64 builds of programs (toolchain programs or not), their package names would be prefixed with mingw-w64-x86_64-. There's also the package group mingw-w64-x86_64-toolchain which you can pacman -S --needed instead to get a somewhat full toolchain.

You may also want to use the urt64 toolchain instead. See this page for more details. (You can e.g. pacman -Ss gdb to find out what's the package name prefix for each of the variants.)

Note that to use any of the toolchain (or any non-msys2 builds of programs), you should use the corresponding "launcher" of shell/terminal instead of msys2.exe.

1. Make sure you have followed the MinGW installation as in https://www.msys2.org/ or if you were using installer from link to installer to install MYSYS then you have to continue from step 5 to install required compiler tools use following command insted of step 6 command

pacman -S --needed base-devel mingw-w64-x86_64-toolchain

3. You should add the same Installation Folder used in step 3 of installation instruction to the system PATH variable or if you have used installer to install the MinGW find the MinGW installation directory by opening your C drive and add that path to system PATH (in my case Ex: C:\msys64\mingw64\bin)

4. Make sure the C:\msys64\mingw64\bin is not empty, if it's empty mostly you haven't continued from the step 5 after installing MYSYS from installer

5. After adding system PATH, close and open cmd window just type path in cmd and enter to make sure your MinGW path is addedd to system PATH, (you can copy paste the output to notepad/notepad++ and search MinGW to find the path)

6. Once MinGW is in the path your gdb command should work (please provide this screenshot of path command output, if it's still didn't work)

The first step is to compile your program with -g to include debugging information within the executable:

g++ -g -o myprog.exe mycode.cpp

Then the program can be loaded into gdb:

gdb myprog.exe

A few commands to get you started:

• break main will cause the debugger to break when main is called. You can also break on lines of code with break FILENAME:LINENO. For example, break mycode.cpp:4 breaks execution whenever the program reaches line 4 of mycode.cpp.
• start starts the program. In your case, you need to set breakpoints before starting the program because it exits quickly.

At a breakpoint:

• print VARNAME. That's how you print values of variables, whether local, static, or global. For example, at the for loop, you can type print temp to print out the value of the temp variable.
• step This is equivalent to "step into".
• next or adv +1 Advance to the next line (like "step over"). You can also advance to a specific line of a specific file with, for example, adv mycode.cpp:8.
• bt Print a backtrace. This is a stack trace, essentially.
• continue Exactly like a "continue" operation of a visual debugger. It causes the program execution to continue until the next break point or the program exits.

The best thing to read is the GDB users' manual.