command: Use different warning messaging in init command and move above potentially confusing output (#27514)

Reference: https://github.com/hashicorp/terraform/issues/27459
Reference: https://github.com/hashicorp/terraform/pull/27507

This follows the change in the plan command to move the development overrides warning above other output from the command that may exhibit unexpected behavior.

command/apply.go

@@ -137,7 +137,7 @@ func (c *ApplyCommand) Run(args []string) int {
 	// Applying changes with dev overrides in effect could make it impossible
 	// to switch back to a release version if the schema isn't compatible,
 	// so we'll warn about it.
-	diags = diags.Append(c.providerDevOverrideWarnings())
+	diags = diags.Append(c.providerDevOverrideRuntimeWarnings())
 
 	// Before we delegate to the backend, we'll print any warning diagnostics
 	// we've accumulated here, since the backend will start fresh with its own

command/e2etest/provider_dev_test.go

@@ -61,8 +61,9 @@ func TestProviderDevOverrides(t *testing.T) {
 	// dev overrides are always ready to use and don't need any special action
 	// to "install" them. This test is mimicking the a happy path of going
 	// directly from "go build" to validate/plan/apply without interacting
-	// with any registries, mirrors, lock files, etc.
-	stdout, _, err = tf.Run("validate")
+	// with any registries, mirrors, lock files, etc. To verify "terraform
+	// init" does actually show a warning, that behavior is tested at the end.
+	stdout, stderr, err = tf.Run("validate")
 	if err != nil {
 		t.Fatalf("unexpected error: %s\n%s", err, stderr)
 	}
@@ -73,4 +74,15 @@ func TestProviderDevOverrides(t *testing.T) {
 	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)
 	}
+
+	stdout, stderr, err = tf.Run("init")
+	if err == nil {
+		t.Fatal("expected error: Failed to query available provider packages")
+	}
+	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)
+	}
 }

command/init.go

@@ -407,6 +407,12 @@ the backend configuration is present and valid.
 // Load the complete module tree, and fetch any missing providers.
 // This method outputs its own Ui.
 func (c *InitCommand) getProviders(config *configs.Config, state *states.State, upgrade bool, pluginDirs []string) (output, abort bool, diags tfdiags.Diagnostics) {
+	// Dev overrides cause the result of "terraform init" to be irrelevant for
+	// any overridden providers, so we'll warn about it to avoid later
+	// confusion when Terraform ends up using a different provider than the
+	// lock file called for.
+	diags = diags.Append(c.providerDevOverrideInitWarnings())
+
 	// First we'll collect all the provider dependencies we can see in the
 	// configuration and the state.
 	reqs, hclDiags := config.ProviderRequirements()
@@ -732,12 +738,6 @@ func (c *InitCommand) getProviders(config *configs.Config, state *states.State,
 	}
 	ctx = evts.OnContext(ctx)
 
-	// Dev overrides cause the result of "terraform init" to be irrelevant for
-	// any overridden providers, so we'll warn about it to avoid later
-	// confusion when Terraform ends up using a different provider than the
-	// lock file called for.
-	diags = diags.Append(c.providerDevOverrideWarnings())
-
 	mode := providercache.InstallNewProvidersOnly
 	if upgrade {
 		mode = providercache.InstallUpgrades

command/meta_providers.go

@@ -152,8 +152,35 @@ func (m *Meta) providerInstallSource() getproviders.Source {
 	return m.ProviderSource
 }
 
-// providerDevOverrideWarnings returns a diagnostics that contains at least
-// one warning if and only if there is at least one provider development
+// providerDevOverrideInitWarnings 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
+// contains error diagnostics.
+//
+// The init command can use this to include a warning that the results
+// may differ from what's expected due to the development overrides. For
+// other commands, providerDevOverrideRuntimeWarnings should be used.
+func (m *Meta) providerDevOverrideInitWarnings() tfdiags.Diagnostics {
+	if len(m.ProviderDevOverrides) == 0 {
+		return nil
+	}
+	var detailMsg strings.Builder
+	detailMsg.WriteString("The following provider development overrides are set in the CLI configuration:\n")
+	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.")
+	return tfdiags.Diagnostics{
+		tfdiags.Sourceless(
+			tfdiags.Warning,
+			"Provider development overrides are in effect",
+			detailMsg.String(),
+		),
+	}
+}
+
+// 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
 // contains error diagnostics.
 //
@@ -162,7 +189,10 @@ func (m *Meta) providerInstallSource() getproviders.Source {
 // not necessary to bother the user with this warning on every command, but
 // it's helpful to return it on commands that have externally-visible side
 // effects and on commands that are used to verify conformance to schemas.
-func (m *Meta) providerDevOverrideWarnings() tfdiags.Diagnostics {
+//
+// See providerDevOverrideInitWarnings for warnings specific to the init
+// command.
+func (m *Meta) providerDevOverrideRuntimeWarnings() tfdiags.Diagnostics {
 	if len(m.ProviderDevOverrides) == 0 {
 		return nil
 	}

command/validate.go

@@ -81,7 +81,7 @@ func (c *ValidateCommand) Run(args []string) int {
 	// not be valid for a stable release, so we'll warn about that in case
 	// the user is trying to use "terraform validate" as a sort of pre-flight
 	// check before submitting a change.
-	diags = diags.Append(c.providerDevOverrideWarnings())
+	diags = diags.Append(c.providerDevOverrideRuntimeWarnings())
 
 	return c.showResults(diags, jsonOutput)
 }