oracle/graal · error · RuntimeException

Could not read the files of the experiment {experimentId}: {

Error message

Could not read the files of the experiment {experimentId}: {message}

What it means

ExperimentParser.parseOrPanic is the convenience entry used by the profdiff CLI: it catches any IOException from parsing an experiment's files and rethrows it as a plain RuntimeException('Could not read the files of the experiment X: <cause>'). It means reading the proftool output or optimization-log directory failed at the I/O level (missing file, non-directory, unreadable), and the tool aborts.

Source

Thrown at compiler/src/org.graalvm.profdiff/src/org/graalvm/profdiff/parser/ExperimentParser.java:368

     * Parses an experiment by reading the provided logs. If anything fails, it throws an unchecked
     * exception.
     *
     * @param experimentId the ID of the parsed experiment
     * @param compilationKind the compilation kind of this experiment
     * @param proftoolPath the file path to the JSON proftool output (mx profjson), can be
     *            {@code null} if the experiment does not have any associated proftool output
     * @param optimizationLogPath the path to the directory containing optimization logs
     * @param warningWriter a writer for warning messages
     * @return an experiment parsed from the provided files
     */
    public static Experiment parseOrPanic(ExperimentId experimentId, Experiment.CompilationKind compilationKind,
                    String proftoolPath, String optimizationLogPath, Writer warningWriter) {
        ExperimentFiles files = new ExperimentFilesImpl(experimentId, compilationKind, proftoolPath, optimizationLogPath);
        ExperimentParser parser = new ExperimentParser(files, warningWriter);
        try {
            return parser.parse();
        } catch (IOException e) {
            throw new RuntimeException("Could not read the files of the experiment " + experimentId + ": " + e.getMessage());
        } catch (ExperimentParserError e) {
            throw new RuntimeException(e.getMessage());
        }
    }
}

View on GitHub (pinned to a66e9ccd1d)

Solutions

1. Verify both the proftool file and the optimization-log directory exist and are readable before running profdiff.
2. Use absolute paths to avoid working-directory surprises.
3. Wait for the measured JVM to finish writing its logs before diffing.
4. Re-run the experiment if the output files are missing.

Example fix

# before
mx profdiff normal-tier --experiment1 exp1 --proftool1 /nonexistent/proftool.json --optimization-log1 /tmp/opt
# after
mx profdiff normal-tier --experiment1 exp1 --proftool1 /data/exp1/proftool.json --optimization-log1 /data/exp1/optlogs/

// Pre-flight all inputs before parseOrPanic
File proftool = new File(proftoolPath);
File optLog = new File(optimizationLogPath);
if (!proftool.isFile() || !proftool.canRead()) throw new IllegalArgumentException("Missing proftool file: " + proftoolPath);
if (!optLog.isDirectory() || !optLog.canRead()) throw new IllegalArgumentException("Bad optimization-log dir: " + optimizationLogPath);

try {
    ExperimentParser.parseOrPanic(experimentId, kind, proftoolPath, optimizationLogPath, warningWriter);
} catch (RuntimeException e) {
    // 'Could not read the files of the experiment X' — resolve the IO cause, then retry once
}

When it happens

Trigger: parseOrPanic with a --proftool path that does not exist, an optimization-log path that is a file or unreadable directory (listFiles() returns null), or any other disk/permission error while reading the experiment's files.

Common situations: Wrong or relative paths resolved from a different cwd, files not yet written (benchmark still running), permission-restricted directories, paths with typos, or data moved after the run.

Related errors

• Failed to print the optimization log to a file: %s
• The provided optimization log path does not denote a directo
• Cannot use the specified log.file
• Invalid directed inlining rules file path: {path}
• Could not read directed inlining rules file: {path}

AI-assisted analysis of oracle/graal@a66e9ccd1d (2026-08-14). Data as JSON: /api/errors/7958f0a3fcdb0e2c. Report an issue: GitHub.