amd64主机交叉编译Golang SDL2静态库到树莓派时缺失依赖报错

交叉编译时出现以下链接错误：

...
cp $WORK/b058/_pkg_.a /.cache/go-build/23/23b77813791e651c39389b15d7f9981669cdee14675f76b632daaa86ced9fc66-d
# internal
# github.com/veandco/go-sdl2/img
/usr/lib/gcc-cross/arm-linux-gnueabi/10/../../../../arm-linux-gnueabi/bin/ld: cannot find -lz
/usr/lib/gcc-cross/arm-linux-gnueabi/10/../../../../arm-linux-gnueabi/bin/ld: cannot find -liconv
/usr/lib/gcc-cross/arm-linux-gnueabi/10/../../../../arm-linux-gnueabi/bin/ld: cannot find -lbcm_host
/usr/lib/gcc-cross/arm-linux-gnueabi/10/../../../../arm-linux-gnueabi/bin/ld: cannot find -lvcos
/usr/lib/gcc-cross/arm-linux-gnueabi/10/../../../../arm-linux-gnueabi/bin/ld: cannot find -lvchiq_arm
collect2: error: ld returned 1 exit status 
...

环境信息 #

• 运行环境：amd64 Ubuntu上的Debian 10（Bullseye）Docker容器
• go.mod配置：

module example.com/sdl-example

go 1.19

require github.com/veandco/go-sdl2 v0.4.33

• Dockerfile内容：

FROM golang:1.19-bullseye

RUN dpkg --add-architecture armhf && \
    apt-get update && apt-get upgrade -y && \
    apt-get install -y \
    apt-utils \
    build-essential \
    glibc-source \
    libc6-armhf-cross \
    libc6-dev-armhf-cross \
    libc6-dev:armhf \
    zlib1g-dev:armhf \
    cmake:armhf \
    autoconf:armhf \
    libtool:armhf \
    gcc-arm-linux-gnueabi \
    crossbuild-essential-armhf \
    binutils-arm-linux-gnueabi \
    libsdl2-dev:armhf \
    libsdl2-ttf-dev:armhf \
    libsdl2-image-dev:armhf

RUN mkdir /.cache && chmod a+rwx /.cache
WORKDIR /build

• 构建脚本：

#!/bin/bash

export GOOS=linux
export GOARCH=arm
export GOARM=6
export CGO_ENABLED=1
export CC=arm-linux-gnueabi-gcc
export PKG_CONFIG_PATH=/usr/lib/aarch64-linux-gnu/pkgconfig
export LD=arm-linux-gnueabi-ld
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/arm-linux-gnueabi/lib

go mod download -x \
    && echo -e "Verify..." \
    && go mod verify \
    && echo "OK"

go build -v -work -x -tags static -o builds/arm5

• 示例代码main.go：

package main

import (
    "github.com/veandco/go-sdl2/sdl"
)

func main() {
    if err := sdl.Init(sdl.INIT_EVERYTHING); err != nil {
        panic(err)
    }
    defer sdl.Quit()

    window, err := sdl.CreateWindow("test", sdl.WINDOWPOS_UNDEFINED, sdl.WINDOWPOS_UNDEFINED,
        800, 600, sdl.WINDOW_SHOWN)
    if err != nil {
        panic(err)
    }
    defer window.Destroy()

    surface, err := window.GetSurface()
    if err != nil {
        panic(err)
    }
    surface.FillRect(nil, 0)

    rect := sdl.Rect{0, 0, 200, 200}
    colour := sdl.Color{R: 255, G: 0, B: 255, A: 255} // purple
    pixel := sdl.MapRGBA(surface.Format, colour.R, colour.G, colour.B, colour.A)
    surface.FillRect(&rect, pixel)
    window.UpdateSurface()

    running := true
    for running {
        for event := sdl.PollEvent(); event != nil; event = sdl.PollEvent() {
            switch event.(type) {
            case *sdl.QuitEvent:
                println("Quit")
                running = false
                break
            }
        }
    }
}

用户疑问：静态编译SDL2时反复出现该错误，担心发行版未提供缺失库，该如何解决？

1. 补充安装缺失的交叉编译依赖包 #

错误中缺失的库对应以下armhf开发包，修改Dockerfile的apt-get install部分，添加这些包：

# 在原有包列表后添加
libcharset-dev:armhf \
libraspberrypi-dev:armhf \
zlib1g-static:armhf

• libcharset-dev:armhf：提供iconv相关的静态库
• libraspberrypi-dev:armhf：提供树莓派硬件相关的bcm_host、vcos、vchiq_arm库
• zlib1g-static:armhf：确保zlib的静态库存在

2. 修正PKG_CONFIG_PATH环境变量 #

构建脚本中PKG_CONFIG_PATH设置为aarch64路径，这是错误的，需要改为armhf的pkgconfig路径：

export PKG_CONFIG_PATH=/usr/lib/arm-linux-gnueabi/pkgconfig

这样pkg-config才能正确找到SDL2等armhf库的配置文件。

3. 调整静态编译参数（可选） #

如果仍然存在链接问题，可以在go build命令中添加额外的链接参数，强制指定静态库路径：

go build -v -work -x -tags static -ldflags="-L/usr/arm-linux-gnueabi/lib -lz -liconv -lbcm_host -lvcos -lvchiq_arm" -o builds/arm5

4. 验证静态库是否存在 #

在Docker容器中执行以下命令，确认所需静态库已安装：

# 检查zlib静态库
find /usr/arm-linux-gnueabi -name "libz.a"
# 检查iconv相关静态库
find /usr/arm-linux-gnueabi -name "libcharset.a"
# 检查树莓派硬件库
find /usr/arm-linux-gnueabi -name "libbcm_host.a"

如果找不到对应文件，说明包未正确安装，需要检查apt源或重新安装对应包。

内容的提问来源于stack exchange，提问作者bytecounter