Since today (9/10) compiling mesa 7.12-devel I get the following error:
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mklib: Making Linux shared library:  r600_dri.so.tmp
g++ -g -O2 -Wall -Wmissing-prototypes -std=c99 -ffast-math -fno-strict-aliasing  -fPIC  -DUSE_X86_64_ASM -D_GNU_SOURCE -DPTHREADS -DHAVE_POSIX_MEMALIGN -DGLX_INDIRECT_RENDERING -DGLX_DIRECT_RENDERING -DUSE_EXTERNAL_DXTN_LIB=1 -DIN_DRI_DRIVER -DHAVE_ALIAS -DHAVE_MINCORE -DHAVE_LIBUDEV -DHAVE_XCB_DRI2 -DXCB_DRI2_CONNECT_DEVICE_NAME_BROKEN -DHAVE_XEXTPROTO_71 -fvisibility=hidden -o r600_dri.so.test ../../../../src/mesa/drivers/dri/common/dri_test.o r600_dri.so.tmp  ../../../../src/mesa/libmesa.a  -ldrm   -lexpat -lm -lpthread -ldl   -lstdc++;
r600_dri.so.tmp: error: undefined reference to 'driInitExtensions'
collect2: ld returned 1 exit status
make[3]: *** [r600_dri.so] Error 1
make[3]: Leaving directory `/home/jos/src/xorg/git-master/mesa/src/gallium/targets/dri-r600'
make[2]: *** [default] Error 1
make[2]: Leaving directory `/home/jos/src/xorg/git-master/mesa/src/gallium/targets'
make[1]: *** [subdirs] Error 1
make[1]: Leaving directory `/home/jos/src/xorg/git-master/mesa/src'
make: *** [default] Error 1
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