This is what happens:

make linux-dri
(cd configs && rm -f current && ln -s linux-dri current)
make default
make[1]: Entering directory `/home/lgi/Mesa-6.4.2'
make[2]: Entering directory `/home/lgi/Mesa-6.4.2/src'
Making sources for linux-dri
mkdir ../lib
make[3]: Entering directory `/home/lgi/Mesa-6.4.2/src/glx/x11'
Makefile:94: depend: No such file or directory
touch depend
/usr/X11R6/bin/makedepend -fdepend -I. -I../../../include -I../../../include/GL/internal -I../../../src/mesa/main -I../../../src/mesa/glapi -I../../../src/mesa/drivers/dri/common `pkg-config --cflags libdrm` -I/usr/X11R6/include ../../../src/mesa/glapi/glapi.c ../../../src/mesa/glapi/glthread.c ../../../src/mesa/main/dispatch.c glcontextmodes.c clientattrib.c compsize.c eval.c glxcmds.c glxext.c glxextensions.c indirect.c indirect_init.c indirect_size.c indirect_window_pos.c indirect_transpose_matrix.c indirect_vertex_array.c indirect_vertex_program.c pixel.c pixelstore.c render2.c renderpix.c single2.c singlepix.c vertarr.c xfont.c glx_pbuffer.c glx_query.c glx_texture_compression.c dri_glx.c XF86dri.c
/bin/sh: /usr/X11R6/bin/makedepend: No such file or directory
make[3]: *** [depend] Error 127
make[3]: Leaving directory `/home/lgi/Mesa-6.4.2/src/glx/x11'
make[2]: *** [subdirs] Error 1
make[2]: Leaving directory `/home/lgi/Mesa-6.4.2/src'
make[1]: *** [default] Error 1
make[1]: Leaving directory `/home/lgi/Mesa-6.4.2'
make: *** [linux-dri] Error 2

Do I need depend and/or makedepend or what?