问题描述
我正在尝试在项目中使用id3lib来获取音频元数据，现在我只在项目内部使用id3lib的这一行
我做了#include <id3/tag.h>，然后在我有的项目中某个地方
ID3_Tag mytag("/home/apoorv/Music/hello.ogg");
当尝试编译它时出现错误
❯ ./build.sh
The Meson build system
Version: 0.56.0
Source dir: /home/apoorv/repos/cpp-projects/wxWidgets/MusicPlayer
Build dir: /home/apoorv/repos/cpp-projects/wxWidgets/MusicPlayer/build
Build type: native build
Project name: MusicPlayer
Project version: undefined
Using 'CXX' from environment with value: 'g++'
C++ compiler for the host machine: g++ (gcc 10.2.0 "g++ (GCC) 10.2.0")
C++ linker for the host machine: g++ ld.bfd 2.35.1
Using 'CXX' from environment with value: 'g++'
Host machine cpu family: x86_64
Host machine cpu: x86_64
wx-config found: YES (/usr/bin/wx-config-gtk3) 3.0.5
Run-time dependency WxWidgets found: YES 3.0.5
Build targets in project: 1
Found ninja-1.10.1 at /usr/bin/ninja
Found runner: ['/usr/bin/ninja']
ninja: Entering directory `.'
[3/3] Linking target musicApp
Failed: musicApp
g++ -o musicApp musicApp.p/src_app.cpp.o musicApp.p/src_frame.cpp.o -Wl,--as-needed -Wl,--no-undefined -pthread -Wl,--start-group -lwx_gtk3u_media-3.0 -lwx_gtk3u_aui-3.0 -lwx_gtk3u_xrc-3.0 -lwx_gtk3u_webview-3.0 -lwx_gtk3u_html-3.0 -lwx_gtk3u_qa-3.0 -lwx_gtk3u_adv-3.0 -lwx_gtk3u_core-3.0 -lwx_baseu_xml-3.0 -lwx_baseu_net-3.0 -lwx_baseu-3.0 -Wl,--end-group
/usr/bin/ld: musicApp.p/src_frame.cpp.o: in function `Frame::Library(wxCommandEvent&)':
/home/apoorv/repos/cpp-projects/wxWidgets/MusicPlayer/build/../src/frame.cpp:495: undefined reference to `ID3_Tag::ID3_Tag(char const*)'
/usr/bin/ld: /home/apoorv/repos/cpp-projects/wxWidgets/MusicPlayer/build/../src/frame.cpp:495: undefined reference to `ID3_Tag::~ID3_Tag()'
/usr/bin/ld: /home/apoorv/repos/cpp-projects/wxWidgets/MusicPlayer/build/../src/frame.cpp:495: undefined reference to `ID3_Tag::~ID3_Tag()'
collect2: error: ld returned 1 exit status
ninja: build stopped: subcommand Failed.
./build.sh: line 12: ./musicApp: No such file or directory
我使用meson作为构建系统，我尝试在id3lib中添加meson.build作为依赖项，但是没有运气
project('MusicPlayer','cpp')
src = [
'src/app.cpp','src/frame.cpp',]
wx = dependency('wxwidgets',modules : ['media','std','aui'])
id3 = dependency('id3lib')
executable('musicApp',src,dependencies : [wx,id3])
我仍然遇到错误
❯ ./build.sh
The Meson build system
Version: 0.56.0
Source dir: /home/apoorv/repos/cpp-projects/wxWidgets/MusicPlayer
Build dir: /home/apoorv/repos/cpp-projects/wxWidgets/MusicPlayer/build
Build type: native build
Project name: MusicPlayer
Project version: undefined
Using 'CXX' from environment with value: 'g++'
C++ compiler for the host machine: g++ (gcc 10.2.0 "g++ (GCC) 10.2.0")
C++ linker for the host machine: g++ ld.bfd 2.35.1
Using 'CXX' from environment with value: 'g++'
Host machine cpu family: x86_64
Host machine cpu: x86_64
wx-config found: YES (/usr/bin/wx-config-gtk3) 3.0.5
Run-time dependency WxWidgets found: YES 3.0.5
Found pkg-config: /usr/bin/pkg-config (1.7.3)
Found CMake: /usr/bin/cmake (3.18.4)
Run-time dependency id3lib found: NO (tried pkgconfig and cmake)
meson.build:12:0: ERROR: Dependency "id3lib" not found,tried pkgconfig and cmake
A full log can be found at /home/apoorv/repos/cpp-projects/wxWidgets/MusicPlayer/build/meson-logs/meson-log.txt
ERROR: Current directory is not a meson build directory: `/home/apoorv/repos/cpp-projects/wxWidgets/MusicPlayer/build`.
Please specify a valid build dir or change the working directory to it.
It is also possible that the build directory was generated with an old
meson version. Please regenerate it in this case.
./build.sh: line 12: ./musicApp: No such file or directory
我在Arch Linux上，确实通过id3lib安装了pacman。
解决方法
id3lib不附带软件包配置（.pc）文件（看起来像no initention），您可以按照链接中的说明自行创建并将其放在PKG_CONIFG_PATH中，但是更容易找到库：
cxx = meson.get_compiler('cpp')
id3 = cxx.find_library('libid3')
- 在这种情况下，尽管您不能在构建时仅依靠代码来依赖/检查库版本。