build: Allow building on non-terraform named directory (hashicorp#25340)

* Allow building on non-terraform named directory

* Fix gofmt errors

* Fix generate-plugins.go unused variable error

Author: perrin4869

scripts/build.sh

@@ -61,7 +61,7 @@ gox \
     -arch="${XC_ARCH}" \
     -osarch="${XC_EXCLUDE_OSARCH}" \
     -ldflags "${LD_FLAGS}" \
-    -output "pkg/{{.OS}}_{{.Arch}}/${PWD##*/}" \
+    -output "pkg/{{.OS}}_{{.Arch}}/terraform" \
     .
 
 # Move all the compiled things to the $GOPATH/bin

scripts/generate-plugins.go

@@ -19,9 +19,8 @@ import (
 const target = "command/internal_plugin_list.go"
 
 func main() {
-	wd, _ := os.Getwd()
-	if filepath.Base(wd) != "terraform" {
-		log.Fatalf("This program must be invoked in the terraform project root; in %s", wd)
+	if isProjectRoot() == false {
+		log.Fatalf("This program must be invoked in the terraform project root")
 	}
 
 	//// Collect all of the data we need about plugins we have in the project
@@ -80,6 +79,15 @@ func makeProviderMap(items []plugin) string {
 	return output
 }
 
+func isProjectRoot() bool {
+	_, err := os.Stat("go.mod")
+	if os.IsNotExist(err) {
+		return false
+	}
+
+	return true
+}
+
 // makeProvisionerMap creates a map of provisioners like this:
 //
 //	"chef":            chefprovisioner.Provisioner,