apache/hadoop · error · IllegalArgumentException

'" + groupStr + "' does not match expected pattern for group

Error message

'" + groupStr + "' does not match expected pattern for group

What it means

Error "'" + groupStr + "' does not match expected pattern for group" thrown in apache/hadoop.

Source

Thrown at hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/FsShellPermissions.java:209

  }

  /**
   * Used to change group of files 
   */
  public static class Chgrp extends Chown {
    public static final String NAME = "chgrp";
    public static final String USAGE = "[-R] GROUP PATH...";
    public static final String DESCRIPTION =
      "This is equivalent to -chown ... :GROUP ...";

    static private final Pattern chgrpPattern = 
      Pattern.compile("^\\s*(" + allowedChars + "+)\\s*$");

    @Override
    protected void parseOwnerGroup(String groupStr) {
      Matcher matcher = chgrpPattern.matcher(groupStr);
      if (!matcher.matches()) {
        throw new IllegalArgumentException(
            "'" + groupStr + "' does not match expected pattern for group");
      }
      owner = null;
      group = matcher.group(1);
    }
  }
}

View on GitHub (pinned to 2add963021)

Solutions

1. Provide a valid group name containing only allowed characters.
2. Verify the group exists on the system (getent group).

When it happens

Trigger: Thrown at hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/FsShellPermissions.java:209 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/b609aeef3113c901. Report an issue: GitHub.