Got an error: Unknown option "DDB_CTF"

Dan Nelson dnelson at
Mon Nov 22 17:08:08 UTC 2010

In the last episode (Nov 22), Weihang Wang said:
> I am a totally newbie to FreeBSD. I am building a custom kernel based on
> FreeBSD 6.0 kernel (I have to use this version cause I need to run an
> application which is only available for FreeBSD 6.0).  I conform to the
> handbook to add the following lines in kernel configuration file to enable
> DTrace support:
> options	DDB_CTF
> makeoptions WITH_CTF=1
> Then I use the following commands to recompile my kernel and install this
> new kernel:
> make buildkernel KERNCONF=KERNELNAME
> make installkernel KERNCONF=KERNELNAME
> The compiling process encounters an error: Unknown option "DDB_CTF", I
> have no idea how to fix this?

Just remove all references to CTF; that's for Dtrace support, which doesn't
exist in the 6.* branch.

You might also want to try running your application on FreeBSD 8.1 after
installing the misc/compat6x package.  Backwards binary compatibility
support is very good.

	Dan Nelson
	dnelson at

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