cmd/geth: print actual error when --unlock fails

cmd/geth/accountcmd.go

@@ -181,13 +181,13 @@ func unlockAccount(ctx *cli.Context, accman *accounts.Manager, address string, i
 	for trials := 0; trials < 3; trials++ {
 		prompt := fmt.Sprintf("Unlocking account %s | Attempt %d/%d", address, trials+1, 3)
 		password := getPassPhrase(prompt, false, i, passwords)
-		if err := accman.Unlock(account, password); err == nil {
+		if err = accman.Unlock(account, password); err == nil {
 			glog.V(logger.Info).Infof("Unlocked account %x", account.Address)
 			return account, password
 		}
 	}
 	// All trials expended to unlock account, bail out
-	utils.Fatalf("Failed to unlock account: %s", address)
+	utils.Fatalf("Failed to unlock account %s (%v)", address, err)
 	return accounts.Account{}, ""
 }
 

cmd/geth/accountcmd_test.go

@@ -168,7 +168,7 @@ Unlocking account f466859ead1932d743d622cb74fc058882e8648a | Attempt 2/3
 Passphrase: {{.InputLine "wrong2"}}
 Unlocking account f466859ead1932d743d622cb74fc058882e8648a | Attempt 3/3
 Passphrase: {{.InputLine "wrong3"}}
-Fatal: Failed to unlock account: f466859ead1932d743d622cb74fc058882e8648a
+Fatal: Failed to unlock account f466859ead1932d743d622cb74fc058882e8648a (could not decrypt key with given passphrase)
 `)
 }
 
@@ -225,6 +225,6 @@ func TestUnlockFlagPasswordFileWrongPassword(t *testing.T) {
 		"--password", "testdata/wrong-passwords.txt", "--unlock", "0,2")
 	defer geth.expectExit()
 	geth.expect(`
-Fatal: Failed to unlock account: 0
+Fatal: Failed to unlock account 0 (could not decrypt key with given passphrase)
 `)
 }