while building tcl-8.4.6 from pkgsrc :

========8<==================

gcc -pipe -c -O2 -march=pentiumpro -O2 -march=pentiumpro -O -DTCL_DBGX= -Wal
l -
Wconversion -Wno-implicit-int -fPIC -I./../generic -I. -DHAVE_UNISTD_H=1 -DH
AVE_
LIMITS_H=1 -DTCL_THREADS=1 -DUSE_THREAD_ALLOC=1 -D_REENTRANT=1 -D_THREAD_SAF
E=1  "-DTCL_WIDE_INT_TYPE=long
long" -DHAVE_GETCWD=1 -DHAVE_OPENDIR=1 -DHAVE_STRSTR=1  -DHAVE_STRTOL=1 -DHA
VE_STRTOLL=1 -DHAVE_STRTOULL=1 -DHAVE_TMPNAM=1 -DHAVE_WAITP
ID=1 -DNO_VALUES_H=1 -DHAVE_SYS_PARAM_H=1 -DUSE_TERMIOS=1 -DHAVE_SYS_TIME_H=
1 -D
TIME_WITH_SYS_TIME=1 -DHAVE_TM_ZONE=1 -DHAVE_GMTIME_R=1 -DHAVE_LOCALTIME_R=1
 -DH
AVE_TM_GMTOFF=1 -DHAVE_TIMEZONE_VAR=1 -DHAVE_ST_BLKSIZE=1 -DSTDC_HEADERS=1 -
DHAV
E_SIGNED_CHAR=1 -DHAVE_PUTENV_THAT_COPIES=1 -DHAVE_LANGINFO=1 -DHAVE_SYS_IOC
TL_H =1 -DHAVE_SYS_FILIO_H=1 -DTCL_SHLIB_EXT=\".so\"
/../generic/tclAsync.c  -fPIC - DPIC -o .libs/tclAsync.o
In file included from ../generic/tclPort.h:27,
                 from ./../generic/tclAsync.c:19:
./generic/../unix/tclUnixPort.h:561: pthread.h: No such file or directory
In file included from ../generic/tclPort.h:27,
                 from ./../generic/tclAsync.c:19:
./generic/../unix/tclUnixPort.h:562: parse error before `TclpMutex'
./generic/../unix/tclUnixPort.h:562: warning: data definition has no type
or st orage class
./generic/../unix/tclUnixPort.h:563: parse error before `*'
./generic/../unix/tclUnixPort.h:564: parse error before `*'
./generic/../unix/tclUnixPort.h:565: parse error before `*'
*** Error code 1

Stop.
make: stopped in /usr/pkgsrc/lang/tcl/work/tcl8.4.6/unix
*** Error code 1

Stop.
make: stopped in /usr/pkgsrc/lang/tcl
*** Error code 1

Stop.
make: stopped in /usr/pkgsrc/lang/tcl
*** Error code 1

Stop.
make: stopped in /usr/pkgsrc/lang/tcl
=====================================

updated pkgsrc twice from cvs, pkgsrc is current as of 12:30EST on 3-23-2004

system is NetBSD 1.6.2 on i386
older versions of tcl and tk have compiled fine with no problems

pthread.h is located at "/usr/pkg/include/pthread.h" and is readable