fatal: the remote end hung up un

在升级pod库时遇到下面的情况，在多方查找资料后，最终解决了这个问题

[!] Error installing FLAnimatedImage
[!] /usr/bin/git clone https://github.com/Flipboard/FLAnimatedImage.git /var/folders/58/p9hmlpx93jng564qhwrfqtpw0000gn/T/d20190530-31669-1y1inta --template= --single-branch --depth 1 --branch 1.0.12

Cloning into '/var/folders/58/p9hmlpx93jng564qhwrfqtpw0000gn/T/d20190530-31669-1y1inta'...
error: RPC failed; curl 18 transfer closed with outstanding read data remaining
fatal: the remote end hung up unexpectedly
fatal: early EOF
fatal: unpack-objects failed

cocoapods 升级库时，遇到这个问题，最终解决办法如下

$ git clone https://github.com/Flipboard/FLAnimatedImage.git --depth 1
$ cd FLAnimatedImage
$ git fetch --unshallow
$ cd -
$ pod update