How to dump goroutine stacktraces?

To print the stack trace for the current goroutine, use PrintStack() from runtime/debug.

PrintStack prints to standard error the stack trace returned by Stack.

For example:

import(
   "runtime/debug"
)
...    
debug.PrintStack()

To print the stack trace for all goroutines use Lookup and WriteTo from runtime/pprof.

func Lookup(name string) *Profile
// Lookup returns the profile with the given name,
// or nil if no such profile exists.

func (p *Profile) WriteTo(w io.Writer, debug int) error
// WriteTo writes a pprof-formatted snapshot of the profile to w.
// If a write to w returns an error, WriteTo returns that error.
// Otherwise, WriteTo returns nil.

Each Profile has a unique name. A few profiles are predefined:

goroutine – stack traces of all current goroutines
heap – a sampling of all heap allocations
threadcreate – stack traces that led to the creation of new OS threads
block – stack traces that led to blocking on synchronization primitives

For example:

pprof.Lookup("goroutine").WriteTo(os.Stdout, 1)