diff --git a/modules/mesh-delivery-checker/internal/check/binaries.go b/modules/mesh-delivery-checker/internal/check/binaries.go
new file mode 100644
index 0000000..5329c61
--- /dev/null
+++ b/modules/mesh-delivery-checker/internal/check/binaries.go
@@ -0,0 +1,42 @@
+package check
+
+import (
+	"fmt"
+	"strings"
+)
+
+// A change that adds or modifies a compiled program fails (issue 1577): it is build output, `go build` in a module's folder
+// writes one beside go.mod, and `git add -A` takes it. The build module's fetch step, which holds the merged clone, reads the
+// first bytes of each changed file and reports the programs (mesh-sdk buildstep.MergeInto); the checker judges the answer.
+
+// NoProgramsReported is the warning of a build module whose fetch answered no programs field: an older module, which cannot
+// tell, so the check does not refuse a program it did not look for.
+const NoProgramsReported = "the build module did not report programs: a compiled program in the change is not refused"
+
+// checkBinariesOf fails a pull request whose change adds or modifies a compiled program, naming each file. It judges the
+// first fetch answer of the pull request, whichever build module gave it; a build module that reports no programs leaves a
+// warning on the check and passes it.
+func (st *state) checkBinariesOf(t *target) verdictPtr {
+	key := fmt.Sprintf("%s#%d", t.pull.Repository, t.pull.Number)
+	if t.fetched.Merge == "" {
+		return nil // no merge was made: nothing was changed to judge
+	}
+	if t.fetched.Programs == nil {
+		st.c.note(fmt.Sprintf("%s: %s (%s)", key, NoProgramsReported, t.module))
+		st.c.warn(key, fmt.Sprintf("a compiled program is not refused: %s reported no programs", t.module))
+		st.j.logf("%s: %s (%s)", key, NoProgramsReported, t.module)
+		return nil
+	}
+	var found []string
+	for _, p := range *t.fetched.Programs {
+		if p.Commit != "" {
+			found = append(found, fmt.Sprintf("%s: a compiled program added in %s and removed later: it stays in history; squash the branch (issue 1577)", p.Path, short12(p.Commit)))
+			continue
+		}
+		found = append(found, p.Path+": a compiled program is build output: remove it and add it to .gitignore (issue 1577)")
+	}
+	if len(found) > 0 {
+		return failed(t.node, fmt.Sprintf("%s: %s", key, strings.Join(found, "; ")))
+	}
+	return nil
+}
diff --git a/modules/mesh-delivery-checker/internal/check/binaries_test.go b/modules/mesh-delivery-checker/internal/check/binaries_test.go
new file mode 100644
index 0000000..2a3ab5e
--- /dev/null
+++ b/modules/mesh-delivery-checker/internal/check/binaries_test.go
@@ -0,0 +1,63 @@
+package check
+
+import (
+	"slices"
+	"strings"
+	"testing"
+
+	"git.novox.be/novox/mesh-sdk/go/delivery"
+)
+
+func TestAChangeWhoseFetchReportsProgramsFailsNamingEachFile(t *testing.T) { // 1577
+	prog := func(p ...string) *[]ProgramFile {
+		out := []ProgramFile{}
+		for _, f := range p {
+			path, commit, _ := strings.Cut(f, "@") // `path@commit`: added by a commit of the branch and removed later
+			out = append(out, ProgramFile{Path: path, Kind: "ELF", Commit: commit})
+		}
+		return &out
+	}
+	for _, c := range []struct {
+		name     string
+		programs *[]ProgramFile
+		fail     []string // paths named; none passes
+		warned   bool     // the build module reported no programs field
+	}{
+		{"none found", prog(), nil, false},
+		{"one program", prog("modules/m/m"), []string{"modules/m/m"}, false},
+		{"two programs", prog("a/x", "b/y"), []string{"a/x", "b/y"}, false},
+		{"added and removed in the branch", prog("gone/prog@0123456789abcdef0123"), []string{"gone/prog: a compiled program added in 0123456789ab and removed later: it stays in history; squash the branch (issue 1577)"}, false},
+		{"an older build module reports nothing", nil, nil, true},
+	} {
+		b := newBench(t)
+		b.fetch.Merge, b.fetch.Programs = "mmmm", c.programs
+		cs := caseOf(t, pullOf(repoA, 7, head1))
+		v := b.judge(t, cs).Verdict
+		if got := slices.ContainsFunc(cs.Notes(), func(n string) bool { return strings.Contains(n, NoProgramsReported) }); got != c.warned {
+			t.Errorf("%s: warned = %v, want %v (%v)", c.name, got, c.warned, cs.Notes())
+		}
+		line := Line(v, cs, cs.Pulls[0], nil, nil, nil)
+		if got := strings.Contains(line, "a compiled program is not refused: mesh-build-go reported no programs"); got != c.warned {
+			t.Errorf("%s: the status line holds the warning = %v, want %v: %s", c.name, got, c.warned, line)
+		}
+		if len(c.fail) == 0 {
+			if v.State != delivery.VerdictPass {
+				t.Errorf("%s: verdict = %+v", c.name, v)
+			}
+			continue
+		}
+		if v.State != delivery.VerdictFail {
+			t.Errorf("%s: verdict = %+v, want a failure", c.name, v)
+			continue
+		}
+		for _, p := range c.fail {
+			want := p
+			if !strings.Contains(p, " added in ") {
+				want = p + ": a compiled program is build output: remove it and add it to .gitignore (issue 1577)"
+			}
+			if !strings.Contains(v.Failed.Words, want) {
+				t.Errorf("%s: words %q do not name %s", c.name, v.Failed.Words, p)
+			}
+		}
+	}
+}
diff --git a/modules/mesh-delivery-checker/internal/check/case.go b/modules/mesh-delivery-checker/internal/check/case.go
index 169d55e..7215adc 100644
--- a/modules/mesh-delivery-checker/internal/check/case.go
+++ b/modules/mesh-delivery-checker/internal/check/case.go
@@ -43,7 +43,9 @@ type Case struct {
 	Try *TryOptions
 
 	notesMu sync.Mutex
-	notes   []string
+	// warnings are, by pull request, what part of its check did not run (Case.warn).
+	warnings map[string]string
+	notes    []string
 	// asks are the ids of the asks the check put on the build seats' streams, in order: a try names them (Try.Asks).
 	asks []string
 	// Progress says what the check is doing, so a check that ran past its bound names the step it was stuck at.
@@ -186,6 +188,23 @@ func (c *Case) note(s string) {
 	}
 }
 
+// warn says of a pull request (pullKey) that a part of its check did not run, in words for its status line (issue 1577).
+func (c *Case) warn(key, words string) {
+	c.notesMu.Lock()
+	defer c.notesMu.Unlock()
+	if c.warnings == nil {
+		c.warnings = map[string]string{}
+	}
+	c.warnings[key] = words
+}
+
+// Warning is what warn said of a pull request, or "".
+func (c *Case) Warning(key string) string {
+	c.notesMu.Lock()
+	defer c.notesMu.Unlock()
+	return c.warnings[key]
+}
+
 // Notes are the words noted on the case, in the order they were noted.
 func (c *Case) Notes() []string {
 	c.notesMu.Lock()
diff --git a/modules/mesh-delivery-checker/internal/check/judge.go b/modules/mesh-delivery-checker/internal/check/judge.go
index f493289..43a0b6b 100644
--- a/modules/mesh-delivery-checker/internal/check/judge.go
+++ b/modules/mesh-delivery-checker/internal/check/judge.go
@@ -489,6 +489,9 @@ func (st *state) askNeeding(ctx context.Context, t *target, merged *[]Fetched, l
 		if v := st.checkPinsOf(ctx, t); v != nil {
 			return v
 		}
+		if v := st.checkBinariesOf(t); v != nil {
+			return v
+		}
 	}
 	ran := 0.0
 	for _, la := range answer.Levels {
diff --git a/modules/mesh-delivery-checker/internal/check/line.go b/modules/mesh-delivery-checker/internal/check/line.go
index f09b839..59d2da8 100644
--- a/modules/mesh-delivery-checker/internal/check/line.go
+++ b/modules/mesh-delivery-checker/internal/check/line.go
@@ -87,18 +87,20 @@ type pieces struct {
 	judged string
 	// carried says, of a carried verdict, the commits it was carried from (ADR 0548 §8); never dropped.
 	carried string
+	// warning says that a part of the check did not run, for instance that an older build module could not refuse a compiled program; never dropped.
+	warning string
 }
 
 // pullKey names a pull request of a case: `<owner/repo>#<number>`.
 func pullKey(p Pull) string { return fmt.Sprintf("%s#%d", p.Repository, p.Number) }
 
 func (p pieces) join(drop int) string {
-	parts := []string{p.head, p.commits, p.carried, p.counts, p.judged}
+	parts := []string{p.head, p.commits, p.carried, p.warning, p.counts, p.judged}
 	switch {
 	case drop < 3 && p.times != "":
 		parts = append(parts, p.times)
 	case drop == 3 && p.shortTimes != "":
-		parts = []string{p.head, p.commits, p.carried, p.shortCounts, p.judged, p.shortTimes}
+		parts = []string{p.head, p.commits, p.carried, p.warning, p.shortCounts, p.judged, p.shortTimes}
 	}
 	if p.over != "" {
 		parts = append(parts, p.over)
@@ -210,6 +212,9 @@ func carriedWords(from map[string]string, v delivery.Verdict, cs *Case, p Pull)
 func parts(v delivery.Verdict, cs *Case, p Pull, builds []BuildNote, slowest []string, judged map[string]string) pieces {
 	var pc pieces
 	pc.judged = judged[pullKey(p)]
+	if cs != nil {
+		pc.warning = cs.Warning(pullKey(p))
+	}
 	commits := short12(p.Head) + " on " + short12(p.Trunk)
 	switch v.State {
 	case delivery.VerdictRunning:
diff --git a/modules/mesh-delivery-checker/internal/check/results.go b/modules/mesh-delivery-checker/internal/check/results.go
index bd61b15..12597a7 100644
--- a/modules/mesh-delivery-checker/internal/check/results.go
+++ b/modules/mesh-delivery-checker/internal/check/results.go
@@ -44,6 +44,17 @@ type Fetched struct {
 	Conflicts []string             `json:"conflicts,omitempty"`
 	Changed   []string             `json:"changed,omitempty"`
 	Trees     map[string]MergeTree `json:"trees,omitempty"`
+	// Programs are the changed files whose first bytes are an executable binary, read by the build module in its workspace
+	// (issue 1577); nil for a build module that does not report it, a pointer to an empty list for one that found none.
+	Programs *[]ProgramFile `json:"programs,omitempty"`
+}
+
+// ProgramFile is a changed file that is a compiled program, and its format (ELF, Mach-O or PE).
+type ProgramFile struct {
+	Path string `json:"path"`
+	Kind string `json:"kind"`
+	// Commit is set for a program a commit of the branch added and a later one removed: it stays in history once merged.
+	Commit string `json:"commit,omitempty"`
 }
 
 // GoPackage is one package of a Go test result.
diff --git a/modules/mesh-delivery-checker/internal/check/testdata/captured/README b/modules/mesh-delivery-checker/internal/check/testdata/captured/README
index 58a30ed..253863c 100644
--- a/modules/mesh-delivery-checker/internal/check/testdata/captured/README
+++ b/modules/mesh-delivery-checker/internal/check/testdata/captured/README
@@ -10,7 +10,7 @@ TestFetchWithABaseMergesAndAnswersThePreview and TestFetchWithAConflictEndsPasse
 into a throwaway test that wrote them out, at mesh-catalog feat/r4c5-checker d5804927 (the git commands are the test's fake,
 so the shas are its constants; the shape and the field names are the module's own marshalling). node-fetch-clean.json is the
 FetchResult json.Marshal of mesh-build-node's fetch (fetch.go, preview.go) in its test TestFetchWithABaseMergesAndAnswersThePreview
-(cmd/mesh-build-node/preview_test.go) at the same commit. Captured on 2026-10-21 for issue 1679.
+(cmd/mesh-build-node/preview_test.go) at the same commit. Captured on 2026-10-21 for issue 1679. Both clean fetches carry `"programs":[]`, which a merging fetch of the build modules answers since issue 1577 (mesh-sdk buildstep.MergeInto's Programs), added by hand to the captured bytes: a fixture without it is an older build module's, and its line warns that no compiled program is refused.
 
 forge-get-file-go-mod.json is the answer of the forge's gitea_get_file (mesh-catalog modules/gitea, tools/index.ts) for modules/mesh-delivery-builder/go.mod of
 novox/mesh-delivery at main, and forge-compare-trunk.json the answer of gitea_compare for novox/mesh-sdk base main, head cb54756c3865 (a commit on the
diff --git a/modules/mesh-delivery-checker/internal/check/testdata/captured/go-fetch-clean.json b/modules/mesh-delivery-checker/internal/check/testdata/captured/go-fetch-clean.json
index ce2e947..a87c222 100644
--- a/modules/mesh-delivery-checker/internal/check/testdata/captured/go-fetch-clean.json
+++ b/modules/mesh-delivery-checker/internal/check/testdata/captured/go-fetch-clean.json
@@ -1 +1 @@
-{"workspace":"mvii1iwu5414e4","commit":"0123456789abcdef0123456789abcdef01234567","modules":["."],"base":"abcdef0123456789abcdef0123456789abcdef01","merge":"fedcba9876543210fedcba9876543210fedcba98","changed":["a.go","modules/m/main.go"],"trees":{"modules/m":{"tree":"1111111111111111111111111111111111111111","manifest":"ca3d163bab055381827226140568f3bef7eaac187cebd76878e0b63e9e442356","locks":{"go.sum":"c5fc83c01e92404452b986527d239140ccf9a48b88e0c268fbf38c2e1429e9c9"}}}}
+{"workspace":"mvii1iwu5414e4","commit":"0123456789abcdef0123456789abcdef01234567","modules":["."],"base":"abcdef0123456789abcdef0123456789abcdef01","merge":"fedcba9876543210fedcba9876543210fedcba98","changed":["a.go","modules/m/main.go"],"programs":[],"trees":{"modules/m":{"tree":"1111111111111111111111111111111111111111","manifest":"ca3d163bab055381827226140568f3bef7eaac187cebd76878e0b63e9e442356","locks":{"go.sum":"c5fc83c01e92404452b986527d239140ccf9a48b88e0c268fbf38c2e1429e9c9"}}}}
diff --git a/modules/mesh-delivery-checker/internal/check/testdata/captured/node-fetch-clean.json b/modules/mesh-delivery-checker/internal/check/testdata/captured/node-fetch-clean.json
index 4c8eedb..55ecfec 100644
--- a/modules/mesh-delivery-checker/internal/check/testdata/captured/node-fetch-clean.json
+++ b/modules/mesh-delivery-checker/internal/check/testdata/captured/node-fetch-clean.json
@@ -1 +1 @@
-{"workspace":"mvii1sxt979f67","commit":"0123456789abcdef0123456789abcdef01234567","modules":["modules/m"],"installed":[],"refused":[],"base":"abcdef0123456789abcdef0123456789abcdef01","merge":"0123456789abcdef0123456789abcdef01234567","changed":["modules/m/package.json"],"trees":{"modules/m":{"tree":"0123456789abcdef0123456789abcdef01234567","manifest":"0581b699d9d05517e69b21f5cedbeb2eee8aba2b205280b561be731594d7feef"}}}
+{"workspace":"mvii1sxt979f67","commit":"0123456789abcdef0123456789abcdef01234567","modules":["modules/m"],"installed":[],"refused":[],"base":"abcdef0123456789abcdef0123456789abcdef01","merge":"0123456789abcdef0123456789abcdef01234567","changed":["modules/m/package.json"],"programs":[],"trees":{"modules/m":{"tree":"0123456789abcdef0123456789abcdef01234567","manifest":"0581b699d9d05517e69b21f5cedbeb2eee8aba2b205280b561be731594d7feef"}}}