Install FreeBSD kernel source after installed freebsd

Install FreeBSD kernel source files, but i have already installed freebsd.

The right way to manual installed kernel source:

Download the tar file that matches the version you installed.
i386: ftp://ftp.freebsd.org/pub/FreeBSD/releases/i386/9.1-RELEASE/src.txz
amd64:ftp://ftp.freebsd.org/pub/FreeBSD/releases/amd64/9.1-RELEASE/src.txz

amd64:ftp://ftp.freebsd.org/pub/FreeBSD/releases/amd64/11.0-RELEASE/src.txz

fetch ftp://ftp.freebsd.org/pub/FreeBSD/releases/amd64/9.1-RELEASE/src.txz

Unpack the archive to /usr/src:

tar -C / -xvzf src.txz

 

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