golang/go · error

read desc failed: %v

Error message

read desc failed: %v

What it means

Returned when readAligned4 fails reading the note descriptor (desc) bytes after the name was read. descsize bytes (4-byte aligned) could not be satisfied, so the build-id payload itself is missing or truncated. The Go build ID lives in this descriptor for NT_VERSION notes.

Source

Thrown at src/cmd/internal/buildid/note.go:63

					break
				}
				return nil, fmt.Errorf("read namesize failed: %v", err)
			}
			err = binary.Read(r, f.ByteOrder, &descsize)
			if err != nil {
				return nil, fmt.Errorf("read descsize failed: %v", err)
			}
			err = binary.Read(r, f.ByteOrder, &noteType)
			if err != nil {
				return nil, fmt.Errorf("read type failed: %v", err)
			}
			noteName, err := readAligned4(r, namesize)
			if err != nil {
				return nil, fmt.Errorf("read name failed: %v", err)
			}
			desc, err := readAligned4(r, descsize)
			if err != nil {
				return nil, fmt.Errorf("read desc failed: %v", err)
			}
			if name == string(noteName) && typ == noteType {
				return desc, nil
			}
		}
	}
	return nil, nil
}

var elfGoNote = []byte("Go\x00\x00")
var elfGNUNote = []byte("GNU\x00")

// The Go build ID is stored in a note described by an ELF PT_NOTE prog
// header. The caller has already opened filename, to get f, and read
// at least 4 kB out, in data.
func readELF(name string, f *os.File, data []byte) (buildid string, err error) {
	// Assume the note content is in the data, already read.
	// Rewrite the ELF header to set shoff and shnum to 0, so that we can pass

View on GitHub (pinned to b6b368adc5)

Solutions

1. Rebuild the binary so the build-id descriptor is written in full.
2. Clean the cache: `go clean -cache`.
3. Confirm the binary was not stripped of its Go note (`file`, `readelf -n <bin>`).
4. Re-fetch the file if transferred incompletely.

if _, err := buildid.ReadFile(bin); err != nil {
    if strings.Contains(err.Error(), "read desc failed") {
        return rebuild(bin) // build-id descriptor missing
    }
    return err
}

When it happens

Trigger: An ELF note declares a descsize larger than the section contains after the header+name, so readAligned4 errors reading desc. The note passes header/name checks but the actual build-id bytes are unavailable.

Common situations: Truncated Go binaries missing the trailing build-id descriptor, corrupt cache entries, partially written link output, or stripped binaries where the descriptor was zeroed.

Related errors

• read namesize failed: %v
• read descsize failed: %v
• read type failed: %v
• read name failed: %v
• cannot find __text section

AI-assisted analysis of golang/go@b6b368adc5 (2026-08-12). Data as JSON: /api/errors/3fcdd0b0adfccd00. Report an issue: GitHub.