What causes "%s: sorry, multi-scan output was not compiled " in DrKLO/Telegram?

Remove -scans and accept default scan layout.

%s: sorry, multi-scan output was not compiled

Error message

%s: sorry, multi-scan output was not compiled

What it means

The -scans flag (multi-scan output script) was passed but the build lacks C_MULTISCAN_FILES_SUPPORTED. jpegtran exits with failure at parse time; the scan script file is never read.

Source

Thrown at TMessagesProj/jni/mozjpeg/jpegtran.c:366

      else if (keymatch(argv[argn], "180", 3))
        select_transform(JXFORM_ROT_180);
      else if (keymatch(argv[argn], "270", 3))
        select_transform(JXFORM_ROT_270);
      else
        usage();

      prefer_smallest = FALSE;

    } else if (keymatch(arg, "scans", 1)) {
      /* Set scan script. */
#ifdef C_MULTISCAN_FILES_SUPPORTED
      if (++argn >= argc)       /* advance to next argument */
        usage();
      prefer_smallest = FALSE;
      scansarg = argv[argn];
      /* We must postpone reading the file in case -progressive appears. */
#else
      fprintf(stderr, "%s: sorry, multi-scan output was not compiled\n",
              progname);
      exit(EXIT_FAILURE);
#endif

    } else if (keymatch(arg, "transpose", 1)) {
      /* Transpose (across UL-to-LR axis). */
      select_transform(JXFORM_TRANSPOSE);
      prefer_smallest = FALSE;

    } else if (keymatch(arg, "transverse", 6)) {
      /* Transverse transpose (across UR-to-LL axis). */
      select_transform(JXFORM_TRANSVERSE);
      prefer_smallest = FALSE;

    } else if (keymatch(arg, "trim", 3)) {
      /* Trim off any partial edge MCUs that the transform can't handle. */
      transformoption.trim = TRUE;
      prefer_smallest = FALSE;

View on GitHub (pinned to 45ab8f4308)

Solutions

Remove -scans and accept default scan layout.
Rebuild with C_MULTISCAN_FILES_SUPPORTED defined (default on for full libjpeg-turbo/mozjpeg; check jpegparam.h and CMake).
Probe for the feature at build time and conditionally enable scan scripts.
Note -progressive also depends on this feature; if -scans fails, -progressive likely will too.

Example fix

# before
./jpegtran -scans script.txt in.jpg > out.jpg
# after
./jpegtran in.jpg > out.jpg   # or rebuild with C_MULTISCAN_FILES_SUPPORTED

Defensive patterns

Strategy: type-guard

Type guard

#ifndef C_MULTISCAN_FILES_SUPPORTED
#error "multi-scan output unavailable; do not pass -scans"
#endif

Prevention

Probe for C_MULTISCAN_FILES_SUPPORTED; -progressive depends on it too.
Rebuild with multi-scan support if scan scripts are needed.
Drop -scans on baseline-only builds.

When it happens

Trigger: Passing -scans <file> on a libjpeg/mozjpeg build compiled without multi-scan support. Baseline-only or single-scan builds reject this option.

Common situations: Embedded/baseline-only libjpeg builds, size-constrained distributions, or misconfigured CMake. Command examples using -scans or -progressive fail identically on these builds.

Related errors

AI-assisted analysis of DrKLO/Telegram@45ab8f4308 (2026-08-14). Data as JSON: /api/errors/b56c6b5fc27cfe5a. Report an issue: GitHub.