nodejs/node · error

-1

-1

Error message

Assembly type "%s" is unknown.

What it means

The assembly type string specified via the -a option (stored in pkgDataFlags[GENCCODE_ASSEMBLY_TYPE]) did not pass checkAssemblyHeaderName(). pkgdata recognizes only specific assembly dialect names that genccode supports (e.g. 'gcc', 'gcc-darwin', 'masm', 'nasm'). An unrecognized value causes immediate exit with code -1 before any assembly code is generated.

Source

Thrown at deps/icu-small/source/tools/pkgdata/pkgdata.cpp:758

                        nullptr,
                        gencFilePath,
                        sizeof(gencFilePath));

                    result = pkg_createWithAssemblyCode(targetDir, mode, gencFilePath);
                    if (result != 0) {
                        fprintf(stderr, "Error generating assembly code for data.\n");
                        return result;
                    } else if (IN_STATIC_MODE(mode)) {
                      if(o->install != nullptr) {
                        if(o->verbose) {
                          fprintf(stdout, "# Installing static library into %s\n", o->install);
                        }
                        result = pkg_installLibrary(o->install, targetDir, noVersion);
                      }
                      return result;
                    }
                } else {
                    fprintf(stderr,"Assembly type \"%s\" is unknown.\n", genccodeAssembly);
                    return -1;
                }
            } else {
                if(o->verbose) {
                  fprintf(stdout, "# Writing object code to %s ..\n", gencFilePath);
                }
                if (o->withoutAssembly) {
#ifdef BUILD_DATA_WITHOUT_ASSEMBLY
                    result = pkg_createWithoutAssemblyCode(o, targetDir, mode);
#else
                    /* This error should not occur. */
                    fprintf(stderr, "Error- BUILD_DATA_WITHOUT_ASSEMBLY is not defined. Internal error.\n");
#endif
                } else {
#ifdef CAN_WRITE_OBJ_CODE
                    /* Try to detect the arch type, use nullptr if unsuccessful */
                    char optMatchArch[10] = { 0 };
                    pkg_createOptMatchArch(optMatchArch);

View on GitHub (pinned to 1b2de5e052)

Solutions

1. Check the valid assembly types by running 'genccode -h' or inspecting checkAssemblyHeaderName() in genccode.c for your ICU version.
2. Use the correct platform-specific type: 'gcc' for GNU as, 'gcc-darwin' for macOS, 'masm' for MSVC x86, 'nasm' for NASM.
3. If unsure which type to use, omit -a entirely and let pkgdata auto-detect, or use BUILD_DATA_WITHOUT_ASSEMBLY mode.

Example fix

// before
//   pkgdata -a linux-x86_64 ...
// after
//   pkgdata -a gcc ...

// Before passing -a to pkgdata, validate the assembly type
#include <string.h>

bool isValidAssemblyType(const char* type) {
    // Known genccode assembly types (varies by ICU version)
    const char* known[] = {"gcc","gcc-darwin","gcc-win32","masm","nasm",nullptr};
    for (int i = 0; known[i]; i++) {
        if (strcmp(type, known[i]) == 0) return true;
    }
    return false;
}

When it happens

Trigger: Passing pkgdata an -a flag with a value not in genccode's known assembly header list. The string is checked after stripping the leading '-a ' prefix (offset by 3 characters at line 735). Valid names depend on the ICU version's genccode implementation.

Common situations: Typo in the assembly type name; using a type valid in a newer ICU version against an older pkgdata build; passing a platform name instead of an assembly dialect name.

Related errors

• Error generating assembly code for data.
• Unable to open or read \"%s\" option file. status = %s\n
• %s: Error calling '%s'\n
• %s: icu-config not found. Fix PATH or specify -O option\n
• %s: Unable to locate pkgdata.inc. Unable to parse the result

AI-assisted analysis of nodejs/node@1b2de5e052 (2026-08-13). Data as JSON: /api/errors/044ab7313931d025. Report an issue: GitHub.