Today I tried to run fedora-review -  while looking at bug 1528414 - and
the run was not successful.  It showed traceback that I was able to
"work-around" by:

--- /usr/lib/python2.7/site-packages/FedoraReview/mock.py       2015-05-04 04:02:43.000000000 -0400
+++ /usr/lib/python2.7/site-packages/FedoraReview/mock.pynew    2020-04-01 05:03:59.634292748 -0400
@@ -158,12 +158,7 @@
             else '/etc/mock'
         path = os.path.join(mockdir, config + '.cfg')
 
-        config_opts = {}
-        with open(path) as f:
-            config = [line for line in f.readlines() if
-                      line.find("config_opts['root']") >= 0]
-        exec config[0]                           # pylint: disable=W0122
-        self.mock_root = config_opts['root']
+        self.mock_root = 'fedora-rawhide-x86_64'
         if Settings.uniqueext:
             self.mock_root += Settings.uniqueext

Then the process hanged on contacting admin.fedoraproject.org:
$ fedora-review -b 1816872 -m fedora-rawhide-x86_64
INFO: Processing bugzilla bug: 1816872
INFO: Getting .spec and .srpm Urls from : 1816872
INFO:   --> SRPM url: https://download.copr.fedorainfracloud.org/results/frostyx/vim-fugitive-pagure/fedora-rawhide-x86_64/01319997-vim-fugitive-pagure/vim-fugitive-pagure-1.2-1.fc33.src.rpm
INFO:   --> Spec url: https://download.copr.fedorainfracloud.org/results/frostyx/vim-fugitive-pagure/fedora-rawhide-x86_64/01319997-vim-fugitive-pagure/vim-fugitive-pagure.spec
INFO: Using review directory: /home/praiskup/1816872-vim-fugitive-pagure
INFO: Downloading .spec and .srpm files
INFO: No upstream for (Source0): vim-fugitive-pagure-1.2.tar.gz
INFO: Running checks and generating report
INFO: Results and/or logs in: /home/praiskup/1816872-vim-fugitive-pagure/results
INFO: Build completed
INFO: Installing built package(s)
INFO: Active plugins: Generic, Shell-api
INFO: Starting new HTTPS connection (1): admin.fedoraproject.org
INFO: Starting new HTTPS connection (1): admin.fedoraproject.org
[HANG]

But that looks like some other issue.