qmake adds /usr/lib absolute path when cross compiling - qt

Question

I need to cross compile a Qt app for arm. This is what I do:
export SDK_MXC_PATH="/path/to/sdk"
export QMAKESPEC="${SDK_MXC_PATH}/usr/mkspecs/devices/linux-imx6-g++/"
export SDK_MXC_BIN="${SDK_MXC_PATH}/toolchain/opt/freescale/usr/local/gcc-4.6.2-glibc-2.13-linaro-multilib-2011.12/fsl-linaro-toolchain/bin/"
export QMAKE="${SDK_MXC_BIN}/qmake"
export PATH="${SDK_MXC_BIN}:${PATH}"
${QMAKE} -spec ${QMAKESPEC}
make
The mkspec file seems to be fine:
include(../common/linux_device_pre.conf)
EGLFS_PLATFORM_HOOKS_SOURCES = $$PWD/qeglfshooks_imx6.cpp
QMAKE_INCDIR += $(SDK_MXC_PATH)/usr/include
QMAKE_LIBDIR += $(SDK_MXC_PATH)/usr/lib
QMAKE_LIBS_EGL += -lEGL -L$(SDK_MXC_PATH)/usr/lib
QMAKE_LIBS_OPENGL_ES2 += -lGLESv2 -lEGL -lGAL -L$(SDK_MXC_PATH)/usr/lib
QMAKE_LIBS_OPENVG += -lOpenVG -lEGL -lGAL -L$(SDK_MXC_PATH)/usr/lib
QMAKE_LIBDIR_OPENGL_ES2 = $(SDK_MXC_PATH)/usr/lib
QMAKE_LFLAGS += -Wl,-rpath-link=$(SDK_MXC_PATH)/usr/lib
QMAKE_CFLAGS_RELEASE += -DLINUX=1 -DEGL_API_FB=1 -O3 -march=armv7-a -mcpu=cortex-a9 -mtune=cortex-a9 -mfloat-abi=softfp -mfpu=neon -ftree-vectorize -fomit-frame-pointer
QMAKE_CXXFLAGS_RELEASE += -DLINUX=1 -DEGL_API_FB=1 -O3 -march=armv7-a -mcpu=cortex-a9 -mtune=cortex-a9 -mfloat-abi=softfp -mfpu=neon -ftree-vectorize -fomit-frame-pointer
include(../common/linux_device_post.conf)
load(qt_config)
Linking fails, with this error:
arm-none-linux-gnueabi-g++ -c -pipe -O2 -DLINUX=1 -DEGL_API_FB=1 -O3 -march=armv7-a -mcpu=cortex-a9 -mtune=cortex-a9 -mfloat-abi=softfp -mfpu=neon -ftree-vectorize -fomit-frame-pointer -Wall -W -D_REENTRANT -fPIE -DQT_NO_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB -I../../path/to/sdk/usr/mkspecs/devices/linux-imx6-g++ -I. -I../../path/to/sdk/usr/include -I../../path/to/sdk/usr/include/QtWidgets -I../../path/to/sdk/usr/include/QtGui -I../../path/to/sdk/usr/include/QtCore -I. -I/path/to/sdk/usr/include -o main.o main.cpp
arm-none-linux-gnueabi-g++ -Wl,-rpath-link=/path/to/sdk/usr/lib -Wl,-O1 -Wl,-rpath,/usr/lib -o qt-hello main.o -L/path/to/sdk/usr/lib -L/path/to/sdk/usr/lib -lQt5Widgets -L/usr/lib -lQt5Gui -lQt5Core -lGLESv2 -lEGL -lGAL -lpthread
/usr/lib/libc_nonshared.a: could not read symbols: File format not recognized
collect2: ld returned 1 exit status
Makefile:183: recipe for target 'qt-hello' failed
make: *** [qt-hello] Error 1
I guess because it is trying to search libraries in /usr/lib
If I manually call the linker, removing -L/usr/lib it works and the executable can run on my target. The command below works, notice that I've removed -L/usr/lib
arm-none-linux-gnueabi-g++ -Wl,-rpath-link=/path/to/sdk/usr/lib -Wl,-O1 -Wl,-rpath,/usr/lib -o qt-hello main.o -L/path/to/sdk/usr/lib -L/path/to/sdk/usr/lib -lQt5Widgets -lQt5Gui -lQt5Core -lGLESv2 -lEGL -lGAL -lpthread
What can I do make qmake working as expected? I don't want to link manually or edit the Makefile each time it is generated by qmake.

Answer 1

Just having the same problem w/ compiling Qt itself - seems to affect anything that calls mesa. But mesa's .pc files are okay.
OTOH, Qt creates broken .pc files. Looking at their monstrous makefile generator code, it seems they ever understood that pkg-config handles dependencies on it's own - IOW: missed the whole point. (well, they
still didn't understand make either).
Yet the old story - still not at all suited for embedded systems.