Did a fresh checkout of xsrc and make fails with:-

making all in /usr/xsrc/local/programs/xsystrace...
gcc -O2 -ansi -Dasm=__asm     -I../../../xfree/xc 
-I../../../xfree/xc/exports/include   -DCSRG_BASED  -DFUNCPROTO=15 
-DNARROWPROTO      -c callbacks.c
gcc -O2 -ansi -Dasm=__asm     -I../../../xfree/xc 
-I../../../xfree/xc/exports/include   -DCSRG_BASED  -DFUNCPROTO=15 
-DNARROWPROTO      -c interface.c
gcc -O2 -ansi -Dasm=__asm     -I../../../xfree/xc 
-I../../../xfree/xc/exports/include   -DCSRG_BASED  -DFUNCPROTO=15 
-DNARROWPROTO      -c main.c
rm -f xsystrace
gcc -o xsystrace -O2 -ansi -Dasm=__asm     -L../../../xfree/xc/exports/lib   
callbacks.o interface.o main.o -lXaw -lXmu -lXt -lSM -lICE -lXpm -lXext -lX11 
-L/usr/X11R6/lib     -Wl,-rpath,/usr/X11R6/lib 
-Wl,-rpath-link,../../../xfree/xc/exports/lib
../../../xfree/xc/exports/lib/libXext.a(extutil.o): In function 
`XextAddDisplay':
extutil.o(.text+0x234): undefined reference to `_XLockMutex_fn'
extutil.o(.text+0x241): undefined reference to `_Xglobal_lock'
extutil.o(.text+0x25a): undefined reference to `_XUnlockMutex_fn'
extutil.o(.text+0x267): undefined reference to `_Xglobal_lock'
../../../xfree/xc/exports/lib/libXext.a(extutil.o): In function 
`XextRemoveDisplay':
extutil.o(.text+0x288): undefined reference to `_XLockMutex_fn'
extutil.o(.text+0x295): undefined reference to `_Xglobal_lock'
extutil.o(.text+0x2b6): undefined reference to `_XUnlockMutex_fn'
extutil.o(.text+0x2c3): undefined reference to `_Xglobal_lock'
extutil.o(.text+0x2f0): undefined reference to `_XUnlockMutex_fn'
extutil.o(.text+0x2fd): undefined reference to `_Xglobal_lock'
../../../xfree/xc/exports/lib/libXext.a(extutil.o): In function 
`XextFindDisplay':
extutil.o(.text+0x33d): undefined reference to `_XLockMutex_fn'
extutil.o(.text+0x34a): undefined reference to `_Xglobal_lock'
extutil.o(.text+0x365): undefined reference to `_XUnlockMutex_fn'
extutil.o(.text+0x372): undefined reference to `_Xglobal_lock'
extutil.o(.text+0x383): undefined reference to `_XUnlockMutex_fn'
extutil.o(.text+0x390): undefined reference to `_Xglobal_lock'
*** Error code 1

Stop.
make: stopped in /usr/xsrc/local/programs/xsystrace
*** Error code 1

Stop.
make: stopped in /usr/xsrc/local/programs
*** Error code 1

Stop.
make: stopped in /usr/xsrc/local
*** Error code 1

Stop.
make: stopped in /usr/xsrc

im running a 1.6zf kernel with 1.6.1 userland on i386.

Any ideas?

Mark