From 627f9eeeff96f60ab45cbe1e4afa89721d544a1a Mon Sep 17 00:00:00 2001
From: PJ <ipriyanshujain@gmail.com>
Date: Tue, 18 Aug 2026 00:17:10 +0530
Subject: [PATCH] fix(implementation-sweep): name every missing required flag,
 in flag order

---
 .../implementation-sweep/main.go              | 26 +++++++++++++-----
 .../implementation-sweep/main_test.go         | 27 +++++++++++++++++++
 2 files changed, 46 insertions(+), 7 deletions(-)

diff --git a/cmd/internal-tools/implementation-sweep/main.go b/cmd/internal-tools/implementation-sweep/main.go
index 7cf2502..e1d48f6 100644
--- a/cmd/internal-tools/implementation-sweep/main.go
+++ b/cmd/internal-tools/implementation-sweep/main.go
@@ -155,16 +155,28 @@ func parseArguments(arguments []string, stderr io.Writer) (config, error) {
 	}
 	configuration.extraArguments = flagSet.Args()
 
-	for name, value := range map[string]string{
-		"--implementations": configuration.implementationsDirectory,
-		"--spec":            configuration.specPath,
-		"--seeds":           seedSpecification,
-		"--output":          configuration.outputDirectory,
+	// Every missing flag is named together, in flag order: stopping at the
+	// first turns one rerun into one rerun per missing flag.
+	var missing []error
+	for _, required := range []struct {
+		name  string
+		value string
+	}{
+		{"--implementations", configuration.implementationsDirectory},
+		{"--spec", configuration.specPath},
+		{"--seeds", seedSpecification},
+		{"--output", configuration.outputDirectory},
 	} {
-		if value == "" {
-			return config{}, fmt.Errorf("%s is required", name)
+		if required.value == "" {
+			missing = append(
+				missing,
+				fmt.Errorf("%s is required", required.name),
+			)
 		}
 	}
+	if err := errors.Join(missing...); err != nil {
+		return config{}, err
+	}
 	if configuration.maxSteps <= 0 {
 		return config{}, fmt.Errorf(
 			"--max-steps must be positive: every implementation needs the same step budget",
diff --git a/cmd/internal-tools/implementation-sweep/main_test.go b/cmd/internal-tools/implementation-sweep/main_test.go
index f9d4d6d..1e5836e 100644
--- a/cmd/internal-tools/implementation-sweep/main_test.go
+++ b/cmd/internal-tools/implementation-sweep/main_test.go
@@ -143,6 +143,33 @@ func TestParseArguments_Rejections(t *testing.T) {
 	}
 }
 
+// Three flags missing is one rerun, not three: the operator is told about all
+// of them at once, in flag order, whatever order the check happened to walk.
+func TestParseArguments_NamesEveryMissingRequiredFlagInFlagOrder(t *testing.T) {
+	_, err := parseArguments(
+		[]string{"--spec", "s", "--max-steps", "10"},
+		io.Discard,
+	)
+	if err == nil {
+		t.Fatal("got no error, want every missing flag named")
+	}
+	message := err.Error()
+	previous := -1
+	for _, name := range []string{"--implementations", "--seeds", "--output"} {
+		at := strings.Index(message, name)
+		if at < 0 {
+			t.Fatalf("got %q, want %s named", message, name)
+		}
+		if at < previous {
+			t.Errorf("got %q, want the flags named in flag order", message)
+		}
+		previous = at
+	}
+	if strings.Contains(message, "--spec") {
+		t.Errorf("got %q, want the supplied --spec left out", message)
+	}
+}
+
 // The seed reaches two independent things, the campaign's own seed and the
 // scaffold's failure stream, and a replay reproduces neither unless they carry
 // the same number.