🐞 Go SDK: go.mod in root directory is overwritten by dagger init when there’s also a package

[helderco]

What is the issue?

Investigation after a report by @sagikazarmark in:

• SDKs should generate files in current working directory by default, not ./dagger #6963 (comment)

It appears that dagger init --sdk go overwrites an existing go.mod when run in a context directory with a go package. The context directory is usually the directory that has .git, but if no parent directory has one, it defaults to the directory where dagger.json is.

Also tested on v0.10.3 and got the same result.

Dagger version

dagger v0.11.1 (registry.dagger.io/engine) darwin/arm64

Steps to reproduce

From a directory that's not inside a git repo:

mkdir testgo
cd testgo
go mod init example.com
cat > main.go <
package main
 
import "fmt"
 
func main() {
    fmt.Println("Hello, World!")
}
EOF
dagger init --sdk go

You'll see that there's no go.mod in dagger/ and the root go.mod has the SDK's dependencies now.

Log output

find .
.
./go.mod
./LICENSE
./dagger
./dagger/dagger.gen.go
./dagger/internal
./dagger/internal/querybuilder
./dagger/internal/querybuilder/marshal.go
./dagger/internal/querybuilder/querybuilder.go
./dagger/internal/dagger
./dagger/internal/dagger/dagger.gen.go
./dagger/internal/telemetry
./dagger/internal/telemetry/batch_processor.go
./dagger/internal/telemetry/processor.go
./dagger/internal/telemetry/proxy.go
./dagger/internal/telemetry/span.go
./dagger/internal/telemetry/init.go
./dagger/internal/telemetry/attrs.go
./dagger/.gitignore
./dagger/.gitattributes
./dagger/main.go
./go.sum
./dagger.json
./main.go

cat go.mod
module example.com
 
go 1.21.6
 
require (
 github.com/99designs/gqlgen v0.17.45
 github.com/Khan/genqlient v0.7.0
 github.com/vektah/gqlparser/v2 v2.5.11
 go.opentelemetry.io/otel v1.25.0
 go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.25.0
 go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.25.0
 go.opentelemetry.io/otel/sdk v1.25.0
 go.opentelemetry.io/otel/trace v1.25.0
 golang.org/x/exp v0.0.0-20240416160154-fe59bbe5cc7f
 golang.org/x/sync v0.7.0
 google.golang.org/grpc v1.63.2
)
 
require (
 github.com/cenkalti/backoff/v4 v4.3.0 // indirect
 github.com/go-logr/logr v1.4.1 // indirect
 github.com/go-logr/stdr v1.2.2 // indirect
 github.com/google/uuid v1.6.0 // indirect
 github.com/grpc-ecosystem/grpc-gateway/v2 v2.19.0 // indirect
 github.com/sosodev/duration v1.2.0 // indirect
 go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.25.0 // indirect
 go.opentelemetry.io/otel/metric v1.25.0 // indirect
 go.opentelemetry.io/proto/otlp v1.1.0 // indirect
 golang.org/x/net v0.23.0 // indirect
 golang.org/x/sys v0.18.0 // indirect
 golang.org/x/text v0.14.0 // indirect
 google.golang.org/genproto/googleapis/api v0.0.0-20240227224415-6ceb2ff114de // indirect
 google.golang.org/genproto/googleapis/rpc v0.0.0-20240401170217-c3f982113cda // indirect
 google.golang.org/protobuf v1.33.0 // indirect
)