apply set-id patch to vendored dependency

We know this is ugly, but there is currently no other way
see knative/eventing#2052

components/event-sources/Makefile

@@ -16,6 +16,8 @@ APP_NAME = event-sources
 APP_PATH = components/event-sources
 BUILDPACK = eu.gcr.io/kyma-project/test-infra/buildpack-golang:go1.12
 SCRIPTS_DIR = ../../common/makefiles
+
+patched_trace = vendor/go.opencensus.io/trace/trace.go
 include $(SCRIPTS_DIR)/generic-make-go.mk
 
 .DEFAULT_GOAL := all
@@ -29,6 +31,7 @@ include $(SCRIPTS_DIR)/generic-make-go.mk
 
 PKG := github.com/kyma-project/kyma/components/event-sources
 
+REPO_ROOT_DIR := $(shell git rev-parse --show-toplevel)
 
 cmds := $(wildcard cmd/*)
 
@@ -37,7 +40,7 @@ cmds := $(wildcard cmd/*)
 all: clean $(cmds)
 
 GOBUILD_FLAGS := -v
-$(cmds): vendor
+$(cmds): $(patched_trace)
 	@echo "+ Building $(notdir $@)"
 	@CGO_ENABLED=0 go build -o $(notdir $@) \
 		$(GOBUILD_FLAGS) \
@@ -53,13 +56,17 @@ vendor: Gopkg.lock
 	@echo '+ Pulling vendored dependencies'
 	@dep ensure -v --vendor-only
 
+$(patched_trace): hack/set-span-id.patch vendor
+	@echo '+ Patching opencensus dependency'
+	@git apply ${REPO_ROOT_DIR}/components/event-sources/hack/set-span-id.patch
+
 
 .PHONY: test
 
 testpkgs := $(shell go list ./... | grep -vE '/apis/|/client/|/cmd/|/testing')
 
 GOTEST_FLAGS := -cover
-test: vendor
+test: $(patched_trace)
 	@echo "+ Performing unit tests"
 	@go test \
 		$(GOTEST_FLAGS) \
@@ -135,7 +142,7 @@ injection: bin/injection-gen
 		--versioned-clientset-package $(PKG)/client/generated/clientset/internalclientset \
 		--external-versions-informers-package $(PKG)/client/generated/informer/externalversions
 
-$(generators_bin): vendor
+$(generators_bin): $(patched_trace)
 	@if [ -d ./vendor/k8s.io/code-generator/cmd/$(notdir $@) ]; then \
 		go build -o bin/$(notdir $@) ./vendor/k8s.io/code-generator/cmd/$(notdir $@); \
 	else \

components/event-sources/hack/set-span-id.patch

@@ -0,0 +1,19 @@
+This patch is directly copied from https://github.com/knative/eventing/blob/master/hack/set-span-id.patch and was originally introduced in PR-1972
+There is currently an open issue to remove this patch again: https://github.com/knative/eventing/issues/2052
+
+diff --git a/vendor/go.opencensus.io/trace/trace.go b/vendor/go.opencensus.io/trace/trace.go
+index 38ead7bf..9e6fe483 100644
+--- a/components/event-sources/vendor/go.opencensus.io/trace/trace.go
++++ b/components/event-sources/vendor/go.opencensus.io/trace/trace.go
+@@ -261,6 +261,11 @@ func startSpanInternal(name string, hasParent bool, parent SpanContext, remotePa
+ 	return span
+ }
+
++func (s *Span) SetSpanID(spanID SpanID) {
++	s.data.SpanID = spanID
++	s.spanContext.SpanID = spanID
++}
++
+ // End ends the span.
+ func (s *Span) End() {
+ 	if s == nil {