fix running go mod tidy on every build.

Makefile

@@ -8,7 +8,7 @@ EXAMPLES := \
 # All source code and documents. Used in spell check.
 ALL_DOCS := $(shell find . -name '*.md' -type f | sort)
 # All directories with go.mod files. Used in go mod tidy.
-ALL_GO_MOD_DIRS := $(shell find . -name 'go.mod' -printf "%h\n" | sort)
+ALL_GO_MOD_DIRS := $(shell find . -type f -name 'go.mod' -exec dirname {} \; | sort)
 
 GOTEST=go test
 GOTEST_OPT?=-v -race -timeout 30s
@@ -33,9 +33,6 @@ precommit: $(TOOLS_DIR)/golangci-lint  $(TOOLS_DIR)/misspell $(TOOLS_DIR)/string
 	PATH="$(abspath $(TOOLS_DIR)):$${PATH}" go generate ./...
 	$(TOOLS_DIR)/golangci-lint run --fix # TODO: Fix this on windows.
 	$(TOOLS_DIR)/misspell -w $(ALL_DOCS)
-
-.PHONY: mod-tidy
-mod-tidy:
 	for dir in $(ALL_GO_MOD_DIRS); do \
 	  echo "go mod tidy in $${dir}"; \
 	  (cd "$${dir}" && go mod tidy); \

example/basic/go.sum

@@ -77,7 +77,6 @@ github.com/klauspost/cpuid v1.2.0/go.mod h1:Pj4uuM528wm8OyEC2QMXAi2YiTZ96dNQPGgo
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
-github.com/lightstep/tracecontext.go v0.0.0-20181129014701-1757c391b1ac/go.mod h1:Frd2bnT3w5FB5q49ENTfVlztJES+1k/7lyWX2+9gq/M=
 github.com/logrusorgru/aurora v0.0.0-20181002194514-a7b3b318ed4e/go.mod h1:7rIyQOR62GCctdiQpZ/zOJlFyk6y+94wXzv6RNZgaR4=
 github.com/magiconair/properties v1.7.6/go.mod h1:PppfXfuXeibc/6YijjN8zIbojt8czPbwD3XqdrwzmxQ=
 github.com/mattn/go-colorable v0.0.9/go.mod h1:9vuHe8Xs5qXnSaW/c/ABM9alt+Vo+STaOChaDxuIBZU=

example/http/go.sum

@@ -81,8 +81,6 @@ github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORN
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
-github.com/lightstep/tracecontext.go v0.0.0-20181129014701-1757c391b1ac h1:+2b6iGRJe3hvV/yVXrd41yVEjxuFHxasJqDhkIjS4gk=
-github.com/lightstep/tracecontext.go v0.0.0-20181129014701-1757c391b1ac/go.mod h1:Frd2bnT3w5FB5q49ENTfVlztJES+1k/7lyWX2+9gq/M=
 github.com/logrusorgru/aurora v0.0.0-20181002194514-a7b3b318ed4e/go.mod h1:7rIyQOR62GCctdiQpZ/zOJlFyk6y+94wXzv6RNZgaR4=
 github.com/magiconair/properties v1.7.6/go.mod h1:PppfXfuXeibc/6YijjN8zIbojt8czPbwD3XqdrwzmxQ=
 github.com/mattn/go-colorable v0.0.9/go.mod h1:9vuHe8Xs5qXnSaW/c/ABM9alt+Vo+STaOChaDxuIBZU=

go.mod

@@ -8,7 +8,6 @@ require (
 	github.com/golangci/golangci-lint v1.17.1
 	github.com/google/go-cmp v0.3.0
 	github.com/hashicorp/golang-lru v0.5.3
-	github.com/lightstep/tracecontext.go v0.0.0-20181129014701-1757c391b1ac
 	golang.org/x/tools v0.0.0-20190524140312-2c0ae7006135
 	google.golang.org/api v0.9.0
 	google.golang.org/grpc v1.22.1

go.sum

@@ -123,8 +123,6 @@ github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORN
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
-github.com/lightstep/tracecontext.go v0.0.0-20181129014701-1757c391b1ac h1:+2b6iGRJe3hvV/yVXrd41yVEjxuFHxasJqDhkIjS4gk=
-github.com/lightstep/tracecontext.go v0.0.0-20181129014701-1757c391b1ac/go.mod h1:Frd2bnT3w5FB5q49ENTfVlztJES+1k/7lyWX2+9gq/M=
 github.com/logrusorgru/aurora v0.0.0-20181002194514-a7b3b318ed4e/go.mod h1:7rIyQOR62GCctdiQpZ/zOJlFyk6y+94wXzv6RNZgaR4=
 github.com/magiconair/properties v1.7.6 h1:U+1DqNen04MdEPgFiIwdOUiqZ8qPa37xgogX/sd3+54=
 github.com/magiconair/properties v1.7.6/go.mod h1:PppfXfuXeibc/6YijjN8zIbojt8czPbwD3XqdrwzmxQ=