SLIC Bug Reports

There are many possible sources of errors when the simulator crashes or exhibits "anomalous" or incorrect behavior. Also, some types of crashes, especially those that occur during batch jobs after a lot of events have been executed, can be difficult to reproduce. Therefore, it is imperative to make all bug reports as detailed as possible, including detailed platform configuration and step-by-step information on repeating the error.


Simulator bugs are tracked using the SLIC Jira.

Use the Create New Issue page to add a bug report.

This is preferable to an email, because the Jira automatically emails the project lead when a report is filed. (This will save the developers from having to fill out the bug report manually based on an email.)

Information for the Bug Report

At a minimum, a good bug report should have the following information.

SLIC Version

The version is very important, because bugs can get fixed in newer versions.

This is a string stored in the file $SLIC_BASE/VERSION.

Simply print the contents of this file.


And paste it into your bug report.

It is also printed when slic starts up.

Operating System.

On a Unix system, execute this command.

uname -a

And paste the output into the bug report.

Compiler Version

From the command-line, execute this command.

g++ -v

And paste the last line into the report.

Run Log

On Unix, a command such as the following will create a log file for your job.

slic [args] &> job_log.txt

Please attach this to the bug report or paste in the relavent sections (if reasonably short).

Input StdHep File

It is vitally important that the StdHep file be specified in the bug report, because many types of errors can occur from malformed or incorrectly processed StdHep files.

If using a "standard" LCD StdHep file from the public data area, give the full FTP URL to that file.

If the StdHep file was produced by you, place it in an accessible location, such as a WWW URL.

Additionally, include the name of the generator(s) that were used (e.g. WHIZARD, PandoraPythia, GRACE, HERWIG, etc.) and the configuration(s) used to produce the file.


Some bugs prevent the creation of the LCIO file.

In the case where an LCIO file was produced, please point to it using the same conventions as given for the StdHep files.

Event Number or List

Oftentimes, errors will occur only on certain event numbers. Please list the event numbers that produce the error in question.

Repeating the Error

If special steps are required to repeat the error, please list them.


Older versions of SLIC and the corresponding Geant4 versions are considered deprecated. If you are using an older version, please consider upgrading to the latest versions of SLIC and LCDD and attempt to repeat the error with this configuration.

  • No labels