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Revision as of 02:21, 19 November 2008 by SamJansen (Talk | contribs) (Run-time errors)

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Platform-specific issues


Python bindings

Python bindings do not build successfully due to a gccxml bug. See the NS-3_Python_Bindings#Caveats page.

If you see "resolving vtable" messages while linking such as the below when you compile on Cygwin, you can safely ignore them:

[530/535] cxx_link: build/debug/examples/wifi-wired-bridging_23.o -> build/debug
Info: resolving vtable for ns3::EmptyAttributeValueby linking to __imp___ZTVN3ns
319EmptyAttributeValueE (auto-import)
Info: resolving vtable for ns3::RandomVariableValueby linking to __imp___ZTVN3ns
319RandomVariableValueE (auto-import)
Info: resolving vtable for ns3::RectangleValueby linking to __imp___ZTVN3ns314Re
ctangleValueE (auto-import)
Info: resolving vtable for ns3::TimeValueby linking to __imp___ZTVN3ns39TimeValu
eE (auto-import)
Info: resolving vtable for ns3::BooleanValueby linking to __imp___ZTVN3ns312Bool
eanValueE (auto-import)



The Network Simulation Cradle is not supported under Cygwin. It is advised to use a Unix-based platform instead. Windows users can use a virtual machine to run e.g. Linux. See e.g. for a free virtual machine.

General build problems

  • Q. What is this kind of build error representative of?
 assert failed. file=../src/core/, line=389, cond="uid != 0"
 Command ['/ns-3-dev/build/debug/examples/mixed-wireless'] exited with code -5
  • A. The system can't find the specified TypeId. Check spelling, and whether it is prefixed with the namespace "ns3::"
  • Q. A required software package is in a non-standard place. How to get waf to find the packages?
  • A. To compile with non-standard link path, use the environment variable LINKFLAGS. Example for bash shell:
LINKFLAGS="-L/tmp" ./waf configure

Run-time errors

  • Q. What is this assertion indicating?
 assert failed. file=debug/ns3/tags.h, line=105, cond="sizeof (T) <= Tags::SIZE"
  • A. The packet tag may be greater than Tags::SIZE (16 bytes)
  • Q. Why does valgrind fail with SIGILL on a simulation using NSC?
  • A. Valgrind does not work under 64-bit mode when running NSC due to lack of support for all the opcodes used. This has been confirmed to work in 32-bit mode.

Debugging tips

  • Q. Is there a way to dereference a Ptr when in gdb?
  • A. yes: p *ptr->m_ptr