[Cocoapods] 安装 realm 出现错误 “Downloading core failed”

问题

通过 pod update 安装 realm时会出现以下错误

  [!] /bin/bash -c 
  set -e
  sh build.sh cocoapods-setup

  core is not a symlink. Deleting...
  Downloading dependency: core 0.97.0
  Downloading core failed:
  curl: (56) SSLRead() return error -36

原因

不可描述（墙）

解决

手动下载realm-sync-cocoa-2.1.1.tar.xz包

mkdir $TMPDIR/core_bin
mv ~/Downloads/realm-sync-cocoa-2.1.1.tar.xz $TMPDIR/core_bin
pod update

顺利解决

参考: https://stackoverflow.com/questions/35953800/installing-realm-via-cocoapods-in-swift