Buildroot编译错误，librt.so:对

Question

我试图使用预先配置的内置建筑工文件编译一个_defconfig映像.更具体的是riscv64_xwin_defconfig，它是一个简单的riscv64映像设置，带有Xorg内置。

由于这是一个相当老的构建，所以我在一个拥有gcc版本5.3.1版本的Fedora 23 Docker容器中这样做，我不认为这是一个问题，因为我可以成功地构建非Xwin riscv64 defconfig。

当Makefile试图构建特定的包"eudev-3.2“时，问题就存在了。

下面是config.log：

configure:3158: $? = 1
configure:3178: checking whether the C compiler works
configure:3200: /home/buildroot-riscv-2018-10-20/output/host/usr/bin/riscv64-buildroot-linux-gnu-gcc -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64  -Os  -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64  conftest.c -lrt >&5
/home/buildroot-riscv-2018-10-20/output/host/usr/lib/gcc/riscv64-buildroot-linux-gnu/7.3.0/../../../../riscv64-buildroot-linux-gnu/bin/ld: warning: libpthread.so.0, needed by /home/buildroot-riscv-2018-10-20/output/host/usr/riscv64-buildroot-linux-gnu/sysroot/usr/lib64/lp64d/librt.so, not found (try using -rpath or -rpath-link)
/home/buildroot-riscv-2018-10-20/output/host/usr/riscv64-buildroot-linux-gnu/sysroot/usr/lib64/lp64d/librt.so: undefined reference to `__pthread_barrier_wait@GLIBC_PRIVATE'
/home/buildroot-riscv-2018-10-20/output/host/usr/riscv64-buildroot-linux-gnu/sysroot/usr/lib64/lp64d/librt.so: undefined reference to `pthread_attr_setstacksize@GLIBC_2.27'
/home/buildroot-riscv-2018-10-20/output/host/usr/riscv64-buildroot-linux-gnu/sysroot/usr/lib64/lp64d/librt.so: undefined reference to `__pthread_barrier_init@GLIBC_PRIVATE'
/home/buildroot-riscv-2018-10-20/output/host/usr/riscv64-buildroot-linux-gnu/sysroot/usr/lib64/lp64d/librt.so: undefined reference to `__pthread_unwind@GLIBC_PRIVATE'
/home/buildroot-riscv-2018-10-20/output/host/usr/riscv64-buildroot-linux-gnu/sysroot/usr/lib64/lp64d/librt.so: undefined reference to `pthread_create@GLIBC_2.27'
/home/buildroot-riscv-2018-10-20/output/host/usr/riscv64-buildroot-linux-gnu/sysroot/usr/lib64/lp64d/librt.so: undefined reference to `pthread_sigmask@GLIBC_2.27'
/home/buildroot-riscv-2018-10-20/output/host/usr/riscv64-buildroot-linux-gnu/sysroot/usr/lib64/lp64d/librt.so: undefined reference to `pthread_once@GLIBC_2.27'
/home/buildroot-riscv-2018-10-20/output/host/usr/riscv64-buildroot-linux-gnu/sysroot/usr/lib64/lp64d/librt.so: undefined reference to `__shm_directory@GLIBC_PRIVATE'
/home/buildroot-riscv-2018-10-20/output/host/usr/riscv64-buildroot-linux-gnu/sysroot/usr/lib64/lp64d/librt.so: undefined reference to `pthread_detach@GLIBC_2.27'
/home/buildroot-riscv-2018-10-20/output/host/usr/riscv64-buildroot-linux-gnu/sysroot/usr/lib64/lp64d/librt.so: undefined reference to `pthread_cancel@GLIBC_2.27'
/home/buildroot-riscv-2018-10-20/output/host/usr/riscv64-buildroot-linux-gnu/sysroot/usr/lib64/lp64d/librt.so: undefined reference to `__pthread_get_minstack@GLIBC_PRIVATE'
collect2: error: ld returned 1 exit status

Answer 1

好像有人忘了显式地链接到libp线程。在末尾添加-lpthread (在-lrt之后)应该可以解决手头的问题。看看你的Makefile，找出您需要在哪里添加-lpthread。