If you want to attach to running processes, use delve, it's awesome. For me personally, even with Go's short build times, you can't just deploy a new binary into a running system to see where a problem lies. Sometimes there is just no way around a traditional debugger.
http://plan9.bell-labs.com/sys/doc/acidpaper.html
or on Unix
https://swtch.com/plan9port/man/man1/acid.html
Watch it in action
Go is really annoying to debug in acid though, because symbols contain dot characters. Somewhat ironically this was done because Unix debuggers were getting confused by the unicode middle dot character, so the unicode middle dot is replaced in the symbol and debug tables with a regular dot.
But on Plan 9 we should not do this process and we should keep the original middle dot.