Swarm FAQ:Common problems

Swarm FAQ

• General
• Objective-C vs. Java
• BLT
• TCL/Tk
• hdf5
• JDKs
• libffi
• tclobjc
• Required programs
• Compiling Swarm
• Unix/Linux
• MS Windows
• Macintosh
• Objective-C
• Java
• C++
• Running programs
• GUI
• Batch mode
• Debugging
• Speeding up code
• Using the Profiler
• Memory leaks

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This is a list of common run-time programs:

MacOS X

Q: Why do I get a error: TkExtra (instance) message?

A: If all your attempts to run Swarm applications on MacOS X end thus:

error: TkExtra (instance)
Abort trap

You need to start X11 before trying to launch a Swarm app with a GUI.

The error is caused by Tcl/Tk trying to open a window and complaining because there is no Xserver on which to open it.