Buildroot gcc 标头与 linux-headers 不匹配

Question

我正在使用 Buildroot 2018.02.7 为 i386 PC 构建一个简单的 Linux 系统，作为为嵌入式 ARM 系统做同样事情的先驱。在构建 util-linux 模块时，我一直遇到这样的问题：

  CC       lib/libcommon_la-path.lo
lib/pager.c:11:17: fatal error: err.h: No such file or directory
 #include <err.h>
                 ^
compilation terminated.
Makefile:8596: recipe for target 'lib/libcommon_la-pager.lo' failed
make[3]: *** [lib/libcommon_la-pager.lo] Error 1

当我在 .../output/build/linux-headers-4.13.8 中查看 linux-headers 源代码树时，找到了该文件。但是 Buildroot 指向的是一组不同的标头，即内置在其 GCC 中的标头：

devuser@3faf730b4a1b:~/pc/buildroot-2018.02.7/output/build/util-linux-2.31.1$ ../../host/bin/i686-buildroot-linux-uclibc-gcc -print-sysroot
/home/devuser/pc/buildroot-2018.02.7/output/host/i686-buildroot-linux-uclibc/sysroot
devuser@3faf730b4a1b:~/pc/buildroot-2018.02.7/output/build/util-linux-2.31.1$ 

而且这两个 /usr/include 子目录明显不同。

我是否错过了 defconfig 文件中某处的配置设置？这是默认配置：

BR2_x86_core2=y
BR2_SSP_REGULAR=y
BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_4_13=y
BR2_UCLIBC_CONFIG="board/pc/dsa_pc_i386_uclibc.config"
BR2_TOOLCHAIN_BUILDROOT_USE_SSP=y
BR2_TOOLCHAIN_BUILDROOT_CXX=y
BR2_TARGET_GENERIC_GETTY_PORT="tty1"
BR2_ROOTFS_POST_IMAGE_SCRIPT="board/pc/post-image.sh support/scripts/genimage.sh"
BR2_ROOTFS_POST_SCRIPT_ARGS="-c board/pc/genimage-bios.cfg"
BR2_LINUX_KERNEL=y
BR2_LINUX_KERNEL_CUSTOM_VERSION=y
BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.13.8"
BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="board/pc/linux.config"
BR2_LINUX_KERNEL_INSTALL_TARGET=y
BR2_LINUX_KERNEL_EXT_XENOMAI=y
BR2_PACKAGE_BUSYBOX_CONFIG="board/pc/dsa_pc_i386_busybox.config"
BR2_PACKAGE_LINUX_FIRMWARE=y
BR2_PACKAGE_LINUX_FIRMWARE_ATHEROS_9170=y
BR2_PACKAGE_LINUX_FIRMWARE_ATHEROS_9271=y
BR2_PACKAGE_LINUX_FIRMWARE_IWLWIFI_3160=y
BR2_PACKAGE_LINUX_FIRMWARE_IWLWIFI_3168=y
BR2_PACKAGE_LINUX_FIRMWARE_IWLWIFI_5000=y
BR2_PACKAGE_LINUX_FIRMWARE_IWLWIFI_6000G2A=y
BR2_PACKAGE_LINUX_FIRMWARE_IWLWIFI_6000G2B=y
BR2_PACKAGE_LINUX_FIRMWARE_IWLWIFI_7260=y
BR2_PACKAGE_LINUX_FIRMWARE_IWLWIFI_7265D=y
BR2_PACKAGE_LINUX_FIRMWARE_IWLWIFI_8000C=y
BR2_PACKAGE_LINUX_FIRMWARE_IWLWIFI_8265=y
BR2_PACKAGE_LINUX_FIRMWARE_RALINK_RT73=y
BR2_PACKAGE_LINUX_FIRMWARE_RALINK_RT2XX=y
BR2_PACKAGE_LINUX_FIRMWARE_RTL_81XX=y
BR2_PACKAGE_LINUX_FIRMWARE_RTL_87XX=y
BR2_PACKAGE_LINUX_FIRMWARE_RTL_88XX=y
BR2_PACKAGE_LINUX_FIRMWARE_RTL_8169=y
BR2_PACKAGE_ACPID=y
BR2_PACKAGE_DBUS=y
BR2_PACKAGE_ZLIB=y
BR2_PACKAGE_LIBFFI=y
BR2_PACKAGE_PCRE=y
BR2_PACKAGE_PCRE_UCP=y
BR2_PACKAGE_READLINE=y
BR2_PACKAGE_WPA_SUPPLICANT=y
BR2_PACKAGE_WPA_SUPPLICANT_DBUS_NEW=y
BR2_PACKAGE_KMOD=y
BR2_PACKAGE_UTIL_LINUX=y
BR2_PACKAGE_UTIL_LINUX_LIBMOUNT=y
BR2_TARGET_ROOTFS_EXT2=y
BR2_TARGET_ROOTFS_EXT2_4=y
BR2_TARGET_ROOTFS_EXT2_SIZE="120M"
# BR2_TARGET_ROOTFS_TAR is not set
BR2_PACKAGE_HOST_GENIMAGE=y

Answer 1

在 uClibc 中启用 UCLIBC_HAS_BSD_ERR。

您有一个自定义的 uClibc 配置。这完全属于“您知道自己在做什么”类别，因为它允许您删除其他软件包所依赖的功能。

在这种情况下，util-linux 依赖于非 Posix err.h 包含。只有在 uClibc 配置中启用了 UCLIBC_HAS_BSD_ERR 时才会安装它。

使用自定义 uClibc 配置遇到类似问题的风险很高。