make: add flake-unit-race-trace goal

To help debug a single race unit test failure, we add a goal that
enables trace logging on stdout.

Author: guggero

Makefile

@@ -232,6 +232,10 @@ flake-unit-race:
 	@$(call print, "Flake hunting races in unit tests.")
 	while [ $$? -eq 0 ]; do make unit-race nocache=1; done
 
+flake-unit-race-trace:
+	@$(call print, "Flake hunting races in unit tests.")
+	while [ $$? -eq 0 ]; do make unit-race log='stdout trace' nocache=1; done
+
 # =============
 # FUZZING
 # =============

make/testing_flags.mk

@@ -74,6 +74,7 @@ endif
 # are provided, we default to "nolog" which will be silent.
 ifneq ($(log),)
 LOG_TAGS := ${log}
+TEST_FLAGS += -test.v
 else
 LOG_TAGS := nolog
 endif