在Ubuntu上为android构建WebRTC时出错

Question

我正试图在Ubuntu 16.04上为Android构建WebRTC。我已遵循以下步骤： https://medium.com/@abdularis/how-to-compile-native-webrtc-from-source-for-android-d0bac8e4c933（我在其他链接中也发现了类似的步骤）

我检查了版本：分支机构负责人/m79

使用命令生成代码时，我遇到以下错误： python tools_webrtc/android/build_aar.py

ERROR at //build/config/android/internal_rules.gni:3051:7: Assertion failed.
      assert(_is_annotation_processor || _is_java_binary || _has_sources)
      ^-----
See //build/config/android/rules.gni:1489:5: whence it was called.
    java_library_impl(target_name) {
    ^-------------------------------
See //build/config/android/rules.gni:1844:5: whence it was called.
    java_library(target_name) {
    ^--------------------------
See //webrtc.gni:850:5: whence it was called.
    android_library(target_name) {
    ^-----------------------------
See //rtc_base/BUILD.gn:1359:3: whence it was called.
  rtc_android_library("base_java") {
  ^---------------------------------
See //BUILD.gn:423:7: which caused the file to be included.
      "rtc_base",
      ^---------
Traceback (most recent call last):
  File "build_aar.py", line 234, in <module>
    sys.exit(main())
  File "build_aar.py", line 230, in main
    args.build_dir, args.extra_gn_switches, args.extra_ninja_switches)
  File "build_aar.py", line 210, in BuildAar
    extra_ninja_switches)
  File "build_aar.py", line 166, in Build
    _RunGN(gn_args_list)
  File "build_aar.py", line 93, in _RunGN
    subprocess.check_call(cmd)
  File "/usr/lib/python2.7/subprocess.py", line 541, in check_call
    raise CalledProcessError(retcode, cmd)
subprocess.CalledProcessError: Command '['/usr/bin/python', '/home/architsinha/work/WebRTC_Android/src/third_party/depot_tools/gn.py', 'gen', '/tmp/tmpuxZSnM/armeabi-v7a', '--args=arm_version=7 use_goma=false target_cpu="arm" is_component_build=false is_debug=false rtc_include_tests=false target_os="android"']' returned non-zero exit status 1

如果我通过运行命令尝试其他方法 gn gen out/Debug --args='target_os="android" target_cpu="arm"' 我得到以下错误：

ERROR at //BUILD.gn:648:20: Assignment had no effect.
      java_files = [
                   ^
You set the variable "java_files" here and it was unused before it went
out of scope.
See //BUILD.gn:647:5: whence it was called.
    junit_binary("android_junit_tests") {
    ^------------------------------------

如何修复此错误？有什么我错过的步骤吗

Answer 1

我也遇到了同样的问题。在处理以下命令时，请确保使用与WebRTC本机开发相同的（only-1）选项卡

首先，请确保您已经安装了以下内容，如果没有，请使用以下命令执行此操作：

 - sudo add-apt-repository ppa:openjdk-r/ppa
 - sudo apt-get install openjdk-8-jdk
 - sudo apt-get install pkg-config
 - sudo apt-get update

---

然后，依次开始以下步骤。根据机器规格和互联网速度，每一步都有自己的时间，因此确保每一步都不间断地完成

1- git clone https://chromium.googlesource.com/chromium/tools/depot_tools.git

2- export PATH="$PATH:${HOME}/depot_tools"

3- mkdir webrtc_android

3.1- cd webrtc_android

4- fetch  nohooks webrtc_android

5- gclient sync

6- cd src/

7- ./build/install-build-deps.sh

8- git branch -r

9- git checkout origin/master

# To check you're in origin/master branch
10- git branch

11- tools_webrtc/android/build_aar.py

---

最后，您将在webrtc_android/src/目录中编译和构建libwebrtc.aar

现在，如果您已经用branch-heads/m79完成了step-7的任务，那么
选择origin/master的branch而不是m79。为此，请尝试以下步骤：

确保您位于以下目录webrtc_android/src/：

 - git checkout origin/master
 # To make sure you're using origin/master
 - git branch
 - gclient revert
 - gclient sync
 - tools_webrtc/android/build_aar.py

希望你能解决你的问题。当前，您正在签出位于origin/master后面的分支，该分支没有构建libwebrtc.aar所需的所有依赖项和模块

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现在，如果您尝试使用这两个过程来构建WebRTC，例如：

1-使用AAR构建工具（./tools_webrtc/android/build_aar.py）

2-使用手动编译（gn gen out/Debug args='target_os="android" target_cpu="arm"'）

2.1-编译（ninja -C out/Debug）

这两个程序都会奏效

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