Set a breakpoint at the TestFind function:

(gdb) b 'regexp.TestFind'
Breakpoint 1 at 0x424908: file /home/user/go/src/regexp/find_test.go, line 148.
Execution has paused at the breakpoint. See which goroutines are running, and what they're doing:

(gdb) info goroutines
  1  waiting runtime.gosched
* 13  running runtime.goexit
Run the program:

(gdb) run
Starting program: /home/user/go/src/regexp/regexp.test

Breakpoint 1, regexp.TestFind (t=0xf8404a89c0) at /home/user/go/src/regexp/find_test.go:148
148	func TestFind(t *testing.T) {

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