init: skip dependencies declared in development override

.changes/v1.15/ENHANCEMENTS-20251107-140221.yaml

@@ -0,0 +1,5 @@
+kind: ENHANCEMENTS
+body: "init: skip dependencies declared in development override. This allows you to use `terraform init` with developer overrides and install dependencies that are not declared in the override file."
+time: 2025-11-07T14:02:21.847382+01:00
+custom:
+    Issue: "27459"

internal/command/e2etest/provider_dev_test.go

@@ -12,6 +12,7 @@ import (
 	"testing"
 
 	"github.com/hashicorp/terraform/internal/e2e"
+	"github.com/hashicorp/terraform/internal/getproviders"
 )
 
 // TestProviderDevOverrides is a test for the special dev_overrides setting
@@ -85,14 +86,91 @@ func TestProviderDevOverrides(t *testing.T) {
 		t.Errorf("stdout doesn't include the warning about development overrides\nwant: %s\n%s", want, got)
 	}
 
-	stdout, stderr, err = tf.Run("init")
-	if err == nil {
-		t.Fatal("expected error: Failed to query available provider packages")
+	stdout, _, _ = tf.Run("init")
+	if err != nil {
+		t.Fatalf("unexpected error: %e", err)
 	}
 	if got, want := stdout, `Provider development overrides are in effect`; !strings.Contains(got, want) {
 		t.Errorf("stdout doesn't include the warning about development overrides\nwant: %s\n%s", want, got)
 	}
-	if got, want := stderr, `Failed to query available provider packages`; !strings.Contains(got, want) {
-		t.Errorf("stderr doesn't include the error about listing unavailable development provider\nwant: %s\n%s", want, got)
+
+	if got, want := stdout, "These providers are not installed as part of init since they"; !strings.Contains(got, want) {
+		t.Errorf("stdout doesn't include init specific warning about consequences of overrides \nwant: %s\n%s", want, got)
+	}
+}
+
+func TestProviderDevOverridesWithProviderToDownload(t *testing.T) {
+	if !canRunGoBuild {
+		// We're running in a separate-build-then-run context, so we can't
+		// currently execute this test which depends on being able to build
+		// new executable at runtime.
+		//
+		// (See the comment on canRunGoBuild's declaration for more information.)
+		t.Skip("can't run without building a new provider executable")
+	}
+	t.Parallel()
+
+	// This test reaches out to releases.hashicorp.com to download the
+	// null provider, so it can only run if network access is allowed.
+	skipIfCannotAccessNetwork(t)
+
+	tf := e2e.NewBinary(t, terraformBin, "testdata/provider-dev-override-with-existing")
+
+	// In order to do a decent end-to-end test for this case we will need a
+	// real enough provider plugin to try to run and make sure we are able
+	// to actually run it. For now we'll use the "test" provider for that,
+	// because it happens to be in this repository and therefore allows
+	// us to avoid drawing in anything external, but we might revisit this
+	// strategy in future if other needs cause us to evolve the test
+	// provider in a way that makes it less suitable for this particular test,
+	// such as if it stops being buildable into an independent executable.
+	providerExeDir := filepath.Join(tf.WorkDir(), "pkgdir")
+	providerExePrefix := filepath.Join(providerExeDir, "terraform-provider-test_")
+	providerExe := e2e.GoBuild("github.com/hashicorp/terraform/internal/provider-simple/main", providerExePrefix)
+	t.Logf("temporary provider executable is %s", providerExe)
+
+	err := ioutil.WriteFile(filepath.Join(tf.WorkDir(), "dev.tfrc"), []byte(fmt.Sprintf(`
+		provider_installation {
+			dev_overrides {
+				"example.com/test/test" = %q
+			}
+			direct {}
+		}
+	`, providerExeDir)), os.ModePerm)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	tf.AddEnv("TF_CLI_CONFIG_FILE=dev.tfrc")
+
+	stdout, stderr, _ := tf.Run("providers")
+	if err != nil {
+		t.Fatalf("unexpected error: %s\n%s", err, stderr)
+	}
+	if got, want := stdout, `provider[example.com/test/test]`; !strings.Contains(got, want) {
+		t.Errorf("configuration should depend on %s, but doesn't\n%s", want, got)
+	}
+
+	stdout, _, err = tf.Run("init")
+	if err != nil {
+		t.Fatalf("unexpected error: %e", err)
+	}
+	if got, want := stdout, `Provider development overrides are in effect`; !strings.Contains(got, want) {
+		t.Errorf("stdout doesn't include the warning about development overrides\nwant: %s\n%s", want, got)
+	}
+	if got, want := stdout, "These providers are not installed as part of init since they were"; !strings.Contains(got, want) {
+		t.Errorf("stdout doesn't include init specific warning about consequences of overrides \nwant: %s\n got: %s", want, got)
+	}
+
+	// Check if the null provider has been installed
+	const providerVersion = "3.1.0" // must match the version in the fixture config
+	pluginDir := filepath.Join(tf.WorkDir(), ".terraform", "providers", "registry.terraform.io", "hashicorp", "null", providerVersion, getproviders.CurrentPlatform.String())
+	pluginExe := filepath.Join(pluginDir, "terraform-provider-null_v"+providerVersion+"_x5")
+	if getproviders.CurrentPlatform.OS == "windows" {
+		pluginExe += ".exe" // ugh
+	}
+
+	if _, err := os.Stat(pluginExe); os.IsNotExist(err) {
+		t.Fatalf("expected plugin executable %s to exist, but it does not", pluginExe)
 	}
 }

internal/command/e2etest/testdata/provider-dev-override-with-existing/pkgdir/.exists

@@ -0,0 +1 @@
+This is where the test will place the temporary build of the test provider.

internal/command/e2etest/testdata/provider-dev-override-with-existing/provider-dev-override.tf

@@ -0,0 +1,22 @@
+terraform {
+  required_providers {
+    # this one is overwritten by dev override
+    simple = {
+      source  = "example.com/test/test"
+      version = "2.0.0"
+    }
+
+    # this one should still be loaded
+    null = {
+      # Our version is intentionally fixed so that we have a fixed
+      # test case here, though we might have to update this in future
+      # if e.g. Terraform stops supporting plugin protocol 5, or if
+      # the null provider is yanked from the registry for some reason.
+      source  = "hashicorp/null"
+      version = "3.1.0"
+    }
+  }
+}
+
+data "simple_resource" "test" {
+}

internal/command/init.go

@@ -258,11 +258,12 @@ func (c *InitCommand) getProviders(ctx context.Context, config *configs.Config,
 	if hclDiags.HasErrors() {
 		return false, true, diags
 	}
+
+	reqs = c.removeDevOverrides(reqs)
 	if state != nil {
 		stateReqs := state.ProviderRequirements()
 		reqs = reqs.Merge(stateReqs)
 	}
-
 	for providerAddr := range reqs {
 		if providerAddr.IsLegacy() {
 			diags = diags.Append(tfdiags.Sourceless(

internal/command/meta_providers.go

@@ -18,6 +18,7 @@ import (
 	builtinProviders "github.com/hashicorp/terraform/internal/builtin/providers"
 	"github.com/hashicorp/terraform/internal/depsfile"
 	"github.com/hashicorp/terraform/internal/getproviders"
+	"github.com/hashicorp/terraform/internal/getproviders/providerreqs"
 	"github.com/hashicorp/terraform/internal/logging"
 	tfplugin "github.com/hashicorp/terraform/internal/plugin"
 	tfplugin6 "github.com/hashicorp/terraform/internal/plugin6"
@@ -176,7 +177,7 @@ func (m *Meta) providerDevOverrideInitWarnings() tfdiags.Diagnostics {
 	for addr, path := range m.ProviderDevOverrides {
 		detailMsg.WriteString(fmt.Sprintf(" - %s in %s\n", addr.ForDisplay(), path))
 	}
-	detailMsg.WriteString("\nSkip terraform init when using provider development overrides. It is not necessary and may error unexpectedly.")
+	detailMsg.WriteString("\nThese providers are not installed as part of init since they were overwritten. If this is unintentional please re-run without the development overrides set.")
 	return tfdiags.Diagnostics{
 		tfdiags.Sourceless(
 			tfdiags.Warning,
@@ -186,6 +187,21 @@ func (m *Meta) providerDevOverrideInitWarnings() tfdiags.Diagnostics {
 	}
 }
 
+func (m *Meta) removeDevOverrides(reqs providerreqs.Requirements) providerreqs.Requirements {
+	// Deep copy the requirements to avoid mutating the input
+	copiedReqs := make(providerreqs.Requirements)
+	for provider, versions := range reqs {
+		// Only copy if the provider is not overridden
+		if _, overridden := m.ProviderDevOverrides[provider]; !overridden {
+			copiedVersions := make(providerreqs.VersionConstraints, len(versions))
+			copy(copiedVersions, versions)
+			copiedReqs[provider] = copiedVersions
+		}
+	}
+
+	return copiedReqs
+}
+
 // providerDevOverrideRuntimeWarnings returns a diagnostics that contains at
 // least one warning if and only if there is at least one provider development
 // override in effect. If not, the result is always empty. The result never