languagetool-org/languagetool · error

basePath does not exist:

Error message

basePath does not exist: 

What it means

RuleSimplifier.run() hard-codes basePath to /lt/git/languagetool/languagetool-language-modules — the maintainer's private checkout path — and throws immediately if that directory does not exist. The tool cannot locate the per-language grammar.xml files it needs to analyze, so it fails fast at startup.

Source

Thrown at languagetool-dev/src/main/java/org/languagetool/dev/archive/RuleSimplifier.java:51

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * Replaces the 'pattern' element in simple rules with the 'regexp' element.
 * WARNING: this is a hack, the rules it produces need to be checked and modified manually!
 */
final class RuleSimplifier {

  private int touchedRulesCount;

  private void run(Language lang) throws IOException {
    File basePath = new File("/lt/git/languagetool/languagetool-language-modules");
    if (!basePath.exists()) {
      throw new RuntimeException("basePath does not exist: " + basePath);
    }
    String langCode = lang.getShortCode();
    File xml = new File(basePath, "/" + langCode + "/src/main/resources/org/languagetool/rules/" + langCode + "/grammar.xml");
    List<String> xmlLines = IOUtils.readLines(new FileReader(xml));
    JLanguageTool tool = new JLanguageTool(lang);
    int totalRules = 0;
    for (Rule rule : tool.getAllActiveRules()) {
      if (!(rule instanceof PatternRule)) {
        continue;
      }
      PatternRule patternRule = (PatternRule) rule;
      String id = patternRule.getFullId();
      if (isSimple((PatternRule)rule)) {
        System.err.println("Simplifying: " + id);
        simplify(patternRule, xmlLines);
      } else {
        System.err.println("Can't simplify: " + id);
      }

View on GitHub (pinned to 2e990059ce)

Solutions

1. Edit RuleSimplifier.java to point basePath at your local checkout, e.g. new File("path/to/languagetool/languagetool-language-modules") or derive it from the current directory.
2. Create a symlink so the expected path exists: mkdir -p /lt/git && ln -s /path/to/your/languagetool /lt/git/languagetool.
3. Better: accept the base path as a main() argument or system property instead of hard-coding it.
4. Verify the directory contains the per-language subdirectories (en, de, ...) with src/main/resources/org/languagetool/rules/<code>/grammar.xml.

Example fix

// before
File basePath = new File("/lt/git/languagetool/languagetool-language-modules");
// after
File basePath = new File(System.getProperty("lt.modules", "./languagetool-language-modules"));
if (!basePath.exists()) {
  throw new RuntimeException("basePath does not exist: " + basePath);
}

File basePath = new File(System.getProperty("lt.modules", "./languagetool-language-modules"));
if (!basePath.isDirectory()) {
  throw new IllegalArgumentException("language modules dir not found: " + basePath);
}

try {
  simplifier.run(language);
} catch (RuntimeException e) {
  if (e.getMessage() != null && e.getMessage().startsWith("basePath does not exist")) {
    System.err.println("Configure -Dlt.modules=<path to languagetool-language-modules>");
  }
}

When it happens

Trigger: Running RuleSimplifier on any machine where /lt/git/languagetool/languagetool-language-modules does not exist — i.e. any environment other than the original developer's workspace, including fresh clones where modules live at ./languagetool-language-modules.

Common situations: Cloning the LanguageTool repo and running dev tools without the required sibling directory layout; running in CI or Docker where the repo is checked out to a different path; renaming or moving the languagetool-language-modules directory after a repository restructure.

Understand the failure class

Background: "File not found" and ENOENT errors: why libraries can't find a file that should exist — this error's family across 50 libraries.

Related errors

• basePath does not exist:
• IOException while writing debug log line
• IOException while writing debug tags
• WrongParameterNumberException
• <dir.getAbsolutePath()> is not a directory, cannot use recur

AI-assisted analysis of languagetool-org/languagetool@2e990059ce (2026-09-06). Data as JSON: /api/errors/1032683e7fd926db. Report an issue: GitHub.