Created attachment 7836 [details] libzlib configure error When I upgraded ubuntu from 16.04 to 18.04, output/build/libzlib-1.2.11 will have a compilation error, because I used the toolchain provided by the bsp vendor. The reason is: ubuntu 18.04/18.10 removed Libgmpv4-dev - Multiprecision arithmetic library developers tools (GCC 4.x compatible) Only reserved: libmpfr6 - multiple precision floating-point computation However, I found that all toolchains provide libmpfr.so by themselves: /opt/Vatics/vtcs_toolchain/arm-eabi-uclibc/usr/lib/libmpfr.so /opt/ralink/arm-buildroot-gcc463-for-ibox/usr/lib/libmpfr.so /opt/ralink/buildroot-gcc463/usr/lib/libmpfr.so /opt/mtk_mipsel_gcc-4.6.3_uclibc-0.9.33/usr/lib/libmpfr.so /opt/GrainMedia/gm813x/toolchain_gnueabi-4.4.0_ARMv5TE/usr/lib/libmpfr.so /opt/mipsel-24kec-linux-uclibc-4.9-2017.07/usr/lib/libmpfr.so /opt/960A/buildroot-gcc463/usr/lib/libmpfr.so Just set the environment variable LD_LIBRARY_PATH to solve it. Export LD_LIBRARY_PATH=/opt/mipsel-24kec-linux-uclibc-4.9-2017.07/usr/lib:$LD_LIBRARY_PATH but, once LD_LIBRARY_PATH is set, an error will be reported in buildroot: You seem to have the current working directory in your LD_LIBRARY_PATH environment variable. This doesn't work. Make: *** [support/dependencies/dependencies.mk:25: core-dependencies] Error 1 How to solve it?
Created attachment 7841 [details] add LD_LIBRARY_PATH
If the programs in your external toolchain use libmpfr.so, but it is not provided by the external toolchain, then the external toolchain is broken. Your patch causes two problems: (1) libmpfr.so is not guaranteed to be installed $(HOST_DIR)/lib. Buildroot only builds/installs host-mpfr if needed, and a typical configuration that uses an external toolchain will not build/install host-mpfr. (2) Passing LD_LIBRARY_PATH pointing to some host libraries will very likely confuse the cross-compilation of some packages. We tried a while ago to use LD_LIBRARY_PATH, and it was a total failure. So, here, you really need to fix the external toolchain itself.