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Last active May 24, 2022 17:30
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This gist shows how to reproduce an issue with `go mod tidy` which apparently fails to apply build constraints correctly.
// +build !go1.16
package main
import (
"io/ioutil"
"github.com/markbates/pkger"
)
var message = embed("/message.txt")
func embed(path string) string {
f, err := pkger.Open(path)
if err != nil {
panic(err)
}
defer f.Close()
bs, err := ioutil.ReadAll(f)
if err != nil {
panic(err)
}
return string(bs)
}
// +build go1.16
package main
import _ "embed"
//go:embed message.txt
var message string
module github.com/campoy/test/gomod-build-issue
go 1.16
require github.com/markbates/pkger v0.17.1
github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/gobuffalo/here v0.6.0 h1:hYrd0a6gDmWxBM4TnrGw8mQg24iSVoIkHEk7FodQcBI=
github.com/gobuffalo/here v0.6.0/go.mod h1:wAG085dHOYqUpf+Ap+WOdrPTp5IYcDAs/x7PLa8Y5fM=
github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
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 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
github.com/markbates/pkger v0.17.1 h1:/MKEtWqtc0mZvu9OinB9UzVN9iYCwLWuyUv4Bw+PCno=
github.com/markbates/pkger v0.17.1/go.mod h1:0JoVlrol20BSywW79rN3kdFFsE5xYM+rSCQDXbLhiuI=
github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk=
github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 h1:qIbj1fsPNlZgppZ+VLlY7N33q108Sa+fhmuc+sWQYwY=
gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
gopkg.in/yaml.v2 v2.2.7 h1:VUgggvou5XRW9mHwD/yXxIYSMtY0zoKQf/v226p2nyo=
gopkg.in/yaml.v2 v2.2.7/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
package main
import "fmt"
func main() {
fmt.Println(message)
}
Hello, world!
# Running this program works for all versions.
$ go1.16rc1 run .
Hello, world!
$ go1.15.7 run .
Hello, world!
# But go mod tidy will fail for version <= go1.15
$ go1.15.7 mod tidy
github.com/campoy/test/gomod-build-issue imports
embed: package embed is not in GOROOT (/Users/francesc/sdk/go1.15.7/src/embed)
# While go1.16 mod tidy works
$ go1.16rc1 mod tidy
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