What causes "couldn't parse the file %s. Error:%s" in nodejs/node?

Run genrb with -v (verbose) to see the specific parse error line number and u_errorName code before this message

couldn't parse the file %s. Error:%s

Error message

couldn't parse the file %s. Error:%s

What it means

genrb's top-level file processor failed to parse a resource bundle .txt source file into an SRBRoot tree. The parse() function returned null or set a UErrorCode failure after reading the file via ucbuf_open. This is genrb's main parse-failure exit path: the file was found and opened, but its contents could not be parsed as valid ICU resource bundle syntax.

Source

Thrown at deps/icu-small/source/tools/genrb/genrb.cpp:680

        fprintf(stderr, "couldn't open file %s\n", openFileName.data());
        return;
    }
    if (ucbuf.isNull() || U_FAILURE(status)) {
        fprintf(stderr, "An error occurred processing file %s. Error: %s\n",
                openFileName.data(), u_errorName(status));
        return;
    }
    /* auto detected popular encodings? */
    if (cp!=nullptr && isVerbose()) {
        printf("autodetected encoding %s\n", cp);
    }
    /* Parse the data into an SRBRoot */
    data.adoptInstead(parse(ucbuf.getAlias(), inputDir, outputDir, filename,
            !omitBinaryCollation, options[NO_COLLATION_RULES].doesOccur, options[ICU4X_MODE].doesOccur, &status));

    if (data.isNull() || U_FAILURE(status)) {
        fprintf(stderr, "couldn't parse the file %s. Error:%s\n", filename, u_errorName(status));
        return;
    }

    // Run filtering before writing pool bundle
    if (filterDir != nullptr) {
        CharString filterFileName(filterDir, status);
        filterFileName.appendPathPart(filename, status);
        if (U_FAILURE(status)) {
            return;
        }

        // Open the file and read it into filter
        SimpleRuleBasedPathFilter filter;
        std::ifstream f(filterFileName.data());
        if (f.fail()) {
            std::cerr << "genrb error: unable to open " << filterFileName.data() << std::endl;
            status = U_FILE_ACCESS_ERROR;
            return;

View on GitHub (pinned to 1b2de5e052)

Solutions

Run genrb with -v (verbose) to see the specific parse error line number and u_errorName code before this message
Open the .txt file at the reported filename and check brace nesting, colons after keys, and string quoting
Verify the file encoding is UTF-8 (or matching BOM) using `file --mime-encoding <filename>`
Diff against a known-good version of the resource bundle to isolate the introduced syntax error
If upgrading ICU, check the changelog for resource bundle grammar changes and update the file accordingly

Example fix

// before: malformed resource bundle entry
root {
    greeting { "Hello" }
    // missing closing brace for nested table
}
// after: properly balanced braces
root {
    greeting { "Hello" }
}

Defensive patterns

Strategy: validation

Validate before calling

# Before running genrb, validate the .txt resource bundle syntax
# Check for balanced braces
python3 -c "
import sys
text = open(sys.argv[1]).read()
depth = 0
for i, c in enumerate(text):
    if c == '{': depth += 1
    elif c == '}': depth -= 1
    if depth < 0:
        print(f'Unmatched closing brace at offset {i}')
        sys.exit(1)
if depth != 0:
    print(f'Unmatched opening braces: {depth} unclosed')
    sys.exit(1)
print('Brace balance OK')
" path/to/bundle.txt

Prevention

Run genrb -v (verbose) during development to catch parse errors early with line numbers
Validate brace nesting and colon-after-key syntax before committing resource bundle edits
Keep resource bundle .txt files under version control so parse errors can be diffed against the last good version
Use a linter or editor plugin for ICU resource bundle syntax if available

When it happens

Trigger: Calling genrb on a .txt file with syntax errors: unclosed braces, missing colons, invalid escape sequences, malformed tagged-string entries, or unparseable nested table/array structures. Also triggered when the file's detected encoding conflicts with its actual byte content, or when ICU4X mode or NO_COLLATION_RULES options produce incompatible parse states.

Common situations: Hand-editing a resource bundle .txt and introducing a brace mismatch or typo; upgrading ICU versions where the resource bundle grammar changed; feeding a non-resource-bundle .txt file (e.g. a README) to genrb by mistake; encoding mismatches after a git checkout on a different OS.

Related errors

AI-assisted analysis of nodejs/node@1b2de5e052 (2026-08-13). Data as JSON: /api/errors/c83c789308f7ec69. Report an issue: GitHub.