安装 pod 时 SSL 证书安装失败?

SSL Certificate installation failed while installing pod?

我在尝试安装其中也包含 crashlytics 的 podfile 时遇到此错误:

Installing Crashlytics (3.3.1)

[!] Error installing Crashlytics
[!] /Applications/XAMPP/xamppfiles/bin/curl -f -L -o /var/folders/1d/2xlstwrn5qd_jf64zznfb2nc0000gn/T/d20150914-12348-1fayiwa/file.zip https://kit-downloads.fabric.io/ios/com.twitter.crashlytics.ios/3.3.1/com.twitter.crashlytics.ios-default.zip --create-dirs

  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
curl: (60) SSL certificate problem: unable to get local issuer certificate
More details here: http://curl.haxx.se/docs/sslcerts.html

curl performs SSL certificate verification by default, using a "bundle"
 of Certificate Authority (CA) public keys (CA certs). If the default
 bundle file isn't adequate, you can specify an alternate file
 using the --cacert option.
If this HTTPS server uses a certificate signed by a CA represented in
 the bundle, the certificate verification probably failed due to a
 problem with the certificate (it might be expired, or the name might
 not match the domain name in the URL).
If you'd like to turn off curl's verification of the certificate, use
 the -k (or --insecure) option.

是什么导致了这个问题?

终于在项目文件夹上解决了这个问题:

echo insecure >> ~/.curlrc