[ns] Big trouble in ns2.1b4a !

[Dong Sun <d.sun@usa.net>]

I was trying to install ns2.1b4a on the FreeBSD 4.2, but I met a big
difficulty when I was running './install'  as follows. Could sombody
give me some help on that? How can I finish the installation with this
two version? Or it is impossible to get them work together?
Thanks -- Dong
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc -c -O  -I./../generic -I.  -DHAVE_GETCWD=1 -DNO_VALUES_H=1
-DHAVE_UNISTD_H=1 -DUSE_TERMIOS=1 -DHAVE_SYS_TIME_H=1
-DTIME_WITH_SYS_TIME=1 -DHAVE_TM_ZONE=1 -DHAVE_TM_GMTOFF=1
-DHAVE_ST_BLKSIZE=1 -DSTDC_HEADERS=1 -DNEED_MATHERR=1
-DHAVE_SIGNED_CHAR=1 -DHAVE_SYS_IOCTL_H=1 -DHAVE_SYS_FILIO_H=1
-DTCL_SHLIB_EXT=\".so\" ./../generic/tclPosixStr.c
./../generic/tclPosixStr.c: In function `Tcl_ErrnoId':
./../generic/tclPosixStr.c:340: duplicate case value
./../generic/tclPosixStr.c:328: this is the first entry for that value
./../generic/tclPosixStr.c: In function `Tcl_ErrnoMsg':
./../generic/tclPosixStr.c:787: duplicate case value
./../generic/tclPosixStr.c:775: this is the first entry for that value
*** Error code 1

Stop in /usr/local/ns-allinone-2.1b4a/tcl8.0/unix.
tcl8.0 make failed! Exiting ...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~