CentOS - Errno 14 problem making ssl connection. Trying other mirror.

Если при выполнии операций yum Вы получаете ошибку связанную с невозможностью получить файл по https, то первым делом Вам нужно выполнить дебаг этой операции через опцию URLGRABBER_DEBUG=1. Для примера:

# URLGRABBER_DEBUG=1 yum makecache 2> /tmp/yum-debug.log
# cat /tmp/yum-debug.log

Если получаем ошибку вида:

* NSS error -5990 или NSS error -8092

а точнее:

< HTTP/1.1 302 Found
< Date: Tue, 07 Jun 2016 13:19:45 GMT
< Server: Apache/2.2.22 (@RELEASE@)
< Location: https://centosup.ispsystem.info/repo/x86_64/repodata/repomd.xml
< Content-Length: 247
< Connection: close
< Content-Type: text/html; charset=iso-8859-1
2016-06-07 16:19:45,351 header ended:
INFO:urlgrabber:header ended:
<
* Closing connection #1
* Issue another request to this URL: 'https://centosup.ispsystem.info/repo/x86_64/repodata/repomd.xml'
* About to connect() to centosup.ispsystem.info port 443 (#1)
*   Trying 92.63.109.213... * connected
* Connected to centosup.ispsystem.info (92.63.109.213) port 443 (#1)
*   CAfile: /etc/pki/tls/certs/ca-bundle.crt
 CApath: none
* NSS error -5990
* Closing connection #1
* SSL connect error
2016-06-07 16:20:15,382 exception: [Errno 14] problem making ssl connection
INFO:urlgrabber:exception: [Errno 14] problem making ssl connection
2016-06-07 16:20:15,382 calling callback: (<bound method YumBaseCli.failureReport of <cli.YumBaseCli object at 0x2012050>>, (), {})
INFO:urlgrabber:calling callback: (<bound method YumBaseCli.failureReport of <cli.YumBaseCli object at 0x2012050>>, (), {})
http://centosup.ispsystem.info/repo/x86_64/repodata/repomd.xml: [Errno 14] problem making ssl connection
Trying other mirror.
2016-06-07 16:20:15,382 MIRROR: failed
INFO:urlgrabber:MIRROR: failed
2016-06-07 16:20:15,382 GR   mirrors: [] 0
INFO:urlgrabber:GR   mirrors: [] 0
2016-06-07 16:20:15,382 MAIN mirrors: [1] 0
INFO:urlgrabber:MAIN mirrors: [2] 0
Error: Cannot retrieve repository metadata (repomd.xml) for repository: centosup. Please verify its path and try again

то первым делом нужно попробовать обновить все пакеты nss:

# yum update nss

для справки:

URLGRABBER_DEBUG=level,filename
where "level" can be either an integer or a log level from the
logging module (DEBUG, INFO, etc).  If the integer is zero or
less, logging will be disabled.  Filename is the filename where
logs will be sent.  If it is "-", then stdout will be used.  If
the filename is empty or missing, stderr will be used. 

 URLGRABBER_DEBUG=1,debug.txt   # log everything to debug.txt
 URLGRABBER_DEBUG=WARNING,-     # log warning and higher to stdout
 URLGRABBER_DEBUG=INFO          # log info and higher to stderr