我将CMake从2.8升级到3.2。 它似乎工作，但因为我收到错误消息
-- downloading...
src='https://googletest.googlecode.com/files/gtest-1.7.0.zip'
dst='... /build/gtest/src/gtest-1.7.0.zip'
timeout='none'
CMake Error at gtest-stamp/download-gtest.cmake:21 (message):
error: downloading
'https://googletest.googlecode.com/files/gtest-1.7.0.zip' failed
status_code: 1
status_string: "Unsupported protocol"
log: Protocol "https" not supported or disabled in libcurl
Closing connection -1
当我将协议从https更改为http时，它运行正常。从支持的协议中删除https的原因是什么？