react-native run-ios 时报 Failed to successfully download 'glog-0.3.5.tar.gz'

今年接触React native 踩了不少坑，遇到如标题所示的问题，我的解决方案如下：

我使用的环境是：React native 0.59.4,XCode:10.2

找到:react-module\react-native\scripts\ios-install-third-party.sh 最底端的内容：

fetch_and_unpack glog-0.3.5.tar.gz https://github.com/google/glog/archive/v0.3.5.tar.gz 61067502c5f9769d111ea1ee3f74e6ddf0a5f9cc "\"$SCRIPTDIR/ios-configure-glog.sh\""
fetch_and_unpack double-conversion-1.1.6.tar.gz https://github.com/google/double-conversion/archive/v1.1.6.tar.gz 1c7d88afde3aaeb97bb652776c627b49e132e8e0
fetch_and_unpack boost_1_63_0.tar.gz https://github.com/react-native-community/boost-for-react-native/releases/download/v1.63.0-0/boost_1_63_0.tar.gz c3f57e1d22a995e608983effbb752b54b6eab741
fetch_and_unpack folly-2018.10.22.00.tar.gz https://github.com/facebook/folly/archive/v2018.10.22.00.tar.gz f70a75bfeb394363d2049a846bba118ffb3b368a

这些是RN依赖的包，要下载，但是即使使用了代理也下载失败，你会发现 fetch_and_unpack是一个脚本，里边包含了curl命令，这个命令是下载网络上资源的，你只要修改一下此处的脚本就能顺利下载并编译了。

修改后脚本：红色标示部分，加上代理 curl -J -L -O -x 127.0.0.1:1087 "$url"

function fetch_and_unpack () {
    file=$1
    url=$2
    hash=$3
    cmd=$4

    retries=4
    fetched=no

    while true; do
        if [ -f "$cachedir/$file" ]; then
           if shasum -p "$cachedir/$file" |
              awk -v hash="$hash" '{exit $1 != hash}'; then
               break
           else
               echo "Incorrect hash:" 2>&1
               shasum -p "$cachedir/$file" 2>&1
               echo "Retrying..." 2>&1
           fi
        fi

        (( retries = retries - 1 ))
        if (( retries < 0 )); then
            file_fail "$cachedir/$file" "Failed to successfully download '$file'"
        fi

        rm -f "$cachedir/$file"
        (cd "$cachedir"; curl -J -L -O -x 127.0.0.1:1087 "$url")
        fetched=yes
    done

    dir=$(basename "$file" .tar.gz)
    if [ "$fetched" = "yes" ] || [ ! -f "third-party/$dir/.installed" ]; then
        (cd third-party;
         rm -rf "$dir"
         echo Unpacking "$cachedir/$file"...
         if ! tar zxf "$cachedir/$file"; then
             file_fail "$cachedir/$file" "Unpacking '$cachedir/$file' failed"
         fi
         cd "$dir"
         eval "${cmd:-true}" && touch .installed)
    fi
}