.

go/xcommon/tracing/cmd/gotrace/testdata/src/a/pkg1/pkg1.go

+package pkg1
+
+import (
+	"net/url"
+
+	// extra import which is used in package but should not be used in tracing
+	"fmt"
+)
+
+// probe receives no args
+//trace:event traceNewTPre()
+
+// probe receives type this package defines
+//trace:event traceNewT(t *T)
+
+type T struct {}
+
+func NewT() *T {
+	traceNewTPre()
+	t := &T{}
+	traceNewT(t)
+	return t
+}
+
+// probe receives type from another package
+//trace:event traceURLParsed(u *url.URL)
+
+func ParseURL(ustr string) (*url.URL, error) {
+	u, err := url.Parse(ustr)
+	if err != nil {
+		return nil, fmt.Errorf("oh my bad: %v", err)
+	}
+
+	traceURLParsed(u)
+	return u, nil
+}
+
+// probe receives builtin type
+//trace:event traceDoSomething(topic string)
+
+func DoSomething(topic string) {
+	traceDoSomething(topic)
+}

go/xcommon/tracing/cmd/gotrace/testdata/src/b/pkg2/pkg2.go

+package pkg2
+
+import "a/pkg1" // TODO should not be needed eventually
+
+//trace:import a/pkg1
+
+
+//trace:event DoSomething(i, j int, q string)
+
+func DoSomething(i, j int, q string) {
+	traceDoSomething(i, j, q)
+}