The SRPM URL is dead.  Instead I tried:
https://copr-be.cloud.fedoraproject.org/results/meeuw/pgcli/fedora-27-x86_64/00738202-pgcli/pgcli-1.9.1-1.fc27.src.rpm
I got a confusing result from fedora-review:

INFO: Processing local files: /home/bothner/Downloads/pgcli-1.9.1-1.fc27.src.rpm
INFO: Getting .spec and .srpm Urls from : Local files in /home/bothner/tmp
INFO:   --> SRPM url: file:///home/bothner/Downloads/pgcli-1.9.1-1.fc27.src.rpm
INFO: Using review directory: /home/bothner/tmp/pgcli
INFO: Downloading (Source0): https://files.pythonhosted.org/packages/source/p/pgcli/pgcli-1.9.1.tar.gz
INFO: Running checks and generating report
ERROR: Exception(/home/bothner/Downloads/pgcli-1.9.1-1.fc27.src.rpm) Config(fedora-27-x86_64) 0 minutes 4 seconds
INFO: Results and/or logs in: /home/bothner/tmp/pgcli/results
ERROR: Command failed: 
INFO: WARNING: Probably non-rawhide buildroot used. Rawhide should be used for most package reviews
ERROR: 'mock build failed, see /home/bothner/tmp/pgcli/results/build.log'
[tmp]1059$ less /home/bothner/tmp/pgcli/results/build.log
[tmp]1060$ uname -a
Linux localhost.localdomain 4.16.8-300.fc28.x86_64 #1 SMP Wed May 9 20:23:40 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux

No useful error messages in /home/bothner/tmp/pgcli/results/build.log.

I'm running Fedora 28.  If you still want this reviewed, I suggest creating a new src.rpm for Fedora 28, and fixing the URLs.

Thanks for checking! I've enable and built the RPMS for 28 and rawhide:

The source RPMs can be found in:

https://copr-be.cloud.fedoraproject.org/results/meeuw/pgcli/fedora-rawhide-x86_64/
https://copr-be.cloud.fedoraproject.org/results/meeuw/pgcli/fedora-28-x86_64/

Then check the directories which start which start with the highest number.

@Per: if you run mock by hand, it shows the following error:
No matching package to install: 'python3-pgspecial >= 1.10.0'

The issue is that OP has two packages under review, and this one depends on the other one. I added the "Depends On" so that the bugs are linked.

So you need to build and install python-pgspecial first, and then build this package. For example like this:
$ mock python-pgspecial-1.10.0-1.fc29.src.rpm --postinstall
$ mock -n pgcli-1.9.1-1.fc29.src.rpm --postinstall

To run fedora-review with an existing mock buildroot:
$ wget https://copr-be.cloud.fedoraproject.org/results/meeuw/pgcli/fedora-rawhide-x86_64/00756263-pgcli/pgcli-1.9.1-1.fc29.src.rpm https://copr-be.cloud.fedoraproject.org/results/meeuw/pgcli/fedora-rawhide-x86_64/00756263-pgcli/pgcli.spec
$ fedora-review -o ' -n' -n pgcli

After changing /etc/mock/default.cfg to fedora-rawhide-x86_64.cfg and then:
$  mock /home/bothner/Downloads/python-pgspecial-1.11.0-4.fc29.src.rpm  --postinstall
$ mock -n /home/bothner/Downloads/pgcli-1.9.1-3.fc29.src.rpm --postinstall

the latter failed:

Start: build setup for pgcli-1.9.1-3.fc29.src.rpm
Building target platforms: x86_64
Building for target x86_64
Wrote: /builddir/build/SRPMS/pgcli-1.9.1-3.fc29.src.rpm
Last metadata expiration check: 0:00:00 ago on Tue 22 May 2018 09:05:34 AM PDT.
No matching package to install: 'python3-pgspecial >= 1.10.0'
Not all dependencies satisfied
Error: Some packages could not be found.
ERROR: Exception(/home/bothner/Downloads/pgcli-1.9.1-3.fc29.src.rpm) Config(fedora-rawhide-x86_64) 0 minutes 2 seconds
INFO: Results and/or logs in: /var/lib/mock/fedora-rawhide-x86_64/result
ERROR: Command failed: 
 # /usr/bin/dnf builddep --installroot /var/lib/mock/fedora-rawhide-x86_64/root/ --releasever 29 /var/lib/mock/fedora-rawhide-x86_64/root//builddir/build/SRPMS/pgcli-1.9.1-3.fc29.src.rpm
Last metadata expiration check: 0:00:00 ago on Tue 22 May 2018 09:05:34 AM PDT.
No matching package to install: 'python3-pgspecial >= 1.10.0'
Not all dependencies satisfied
Error: Some packages could not be found.

Could this be a python/python2/python3 issue?

FWIW I also tried:
$ mock --resultdir pg /home/bothner/Downloads/python-pgspecial-1.11.0-4.fc29.src.rpm /home/bothner/Downloads/pgcli-1.9.1-3.fc29.src.rpm --postinstall
with similar result.

python3-pgspecial is a new dependency (which isn't in Fedora yet).

you can download python3-pgspecial from copr:
copr enable meeuw/pgcli
dnf download python3-pgspecial

Then you can run fedora-review -n pgcli -L /path/to/pgspecial to get a fedora-review.

That did not work:

$ sudo copr enable meeuw/pgcli
usage: copr [-h] [--debug] [--config CONFIG] [--version]
            {whoami,list,mock-config,create,modify,delete,fork,build,buildpypi,buildgem,buildcustom,buildfedpkg,buildtito,buildmock,buildscm,status,download-build,cancel,watch-build,delete-build,edit-chroot,get-chroot,add-package-tito,edit-package-tito,add-package-pypi,edit-package-pypi,add-package-mockscm,edit-package-mockscm,add-package-scm,edit-package-scm,add-package-rubygems,edit-package-rubygems,add-package-custom,edit-package-custom,list-packages,list-package-names,get-package,delete-package,reset-package,build-package,build-module}

I think for me to try to figure this all out is counter-productive and is wasting everybody's time. pgcli is too complex a package (in terms of dependencies and python issues) for me to usefully review.  I'm not even a python programmer - tough I do have quite an interest in repls and clis.  I'm requiring too much hand-holding and teaching of new commands that I will immediately forget.

(I'd say my areas of Fedora-relevant expertise are C, autotools, Java, XML, JavaScript (weak on npm and related tools - but I need to solidify that), and the Scheme/Lisp languages.)

oh my bad, it is: dnf copr enable meeuw/pgcli ... sorry

A problem not with pgcli but with fedora-review/mock is a terrible error message.
I've tried running fedora-review in various ways, and I typically get:

INFO: Running checks and generating report
ERROR: Exception(/home/bothner/tmp/pgcli-1.9.1-3.fc28.src.rpm) Config(fedora-rawhide-x86_64) 12 minutes 42 seconds
INFO: Results and/or logs in: /home/bothner/tmp/review-pgcli/results
ERROR: Command failed: 
ERROR: 'mock build failed, see /home/bothner/tmp/review-pgcli/results/build.log'
[tmp]1013$ less /home/bothner/tmp/review-pgcli/results/build.log

Then I look at /home/bothner/tmp/review-pgcli/results/build.log and *there is no error message there*.  I see:

Executing command: ['/usr/bin/systemd-nspawn', '-q', '-M', '9ef15e6bf216491ba8829a9ce86f2af0', '-D', '/var/lib/mock/fedora-rawhide-x86_64/root', '-a', '--setenv=TERM=vt100', '--setenv=SHELL=/bin/bash', '--setenv=HOME=/builddir', '--setenv=HOSTNAME=mock', '--setenv=PATH=/usr/bin:/bin:/usr/sbin:/sbin', '--setenv=PROMPT_COMMAND=printf "\\033]0;<mock-chroot>\\007"', '--setenv=PS1=<mock-chroot> \\s-\\v\\$ ', '--setenv=LANG=en_US.UTF-8', '-u', 'mockbuild', 'bash', '--login', '-c', '/usr/bin/rpmbuild -bs --target x86_64 --nodeps /builddir/build/SPECS/pgcli.spec'] with env {'TERM': 'vt100', 'SHELL': '/bin/bash', 'HOME': '/builddir', 'HOSTNAME': 'mock', 'PATH': '/usr/bin:/bin:/usr/sbin:/sbin', 'PROMPT_COMMAND': 'printf "\\033]0;<mock-chroot>\\007"', 'PS1': '<mock-chroot> \\s-\\v\\$ ', 'LANG': 'en_US.UTF-8'} and shell False
Building target platforms: x86_64
Building for target x86_64
Wrote: /builddir/build/SRPMS/pgcli-1.9.1-3.fc29.src.rpm
Child return code was: 0
Mock Version: 1.4.10

(The "and shell False" is a bit weird but I have no idea if it is legitimate.)

This is a serious usability bug in mock and/or fedora-review: To write an error message 'mock build failed, see FILENAME' and then have FILENAME not contain any error message is pretty bad.  (Not the fault of pgcli, of course.)

(In reply to Per Bothner from comment #8)
> A problem not with pgcli but with fedora-review/mock is a terrible error
> message.
> I've tried running fedora-review in various ways, and I typically get:
> 
Look at root.log and search for "Error:"

Getting a bit firther, with
   $ fedora-review -n pgcli -L `pwd`
INFO: Processing local files: pgcli
INFO: Getting .spec and .srpm Urls from : Local files in /home/bothner/tmp
INFO:   --> SRPM url: file:///home/bothner/tmp/pgcli-1.9.1-3.fc28.src.rpm
INFO:   --> Spec url: file:///home/bothner/tmp/pgcli.spec
INFO: Using review directory: /home/bothner/tmp/review-pgcli
INFO: Downloading (Source0): https://files.pythonhosted.org/packages/source/p/pgcli/pgcli-1.9.1.tar.gz
INFO: Running checks and generating report
INFO: Install command returned error code 30
ERROR: 'While building: INFO: mock.py version 1.4.10 starting (python version = 3.6.5)...\nStart: init plugins\nINFO: selinux disabled\nFinish: init plugins\nStart: run\nStart: chroot init\nINFO: calling preinit hooks\nINFO: enabled root cache\nINFO: enabled dnf cache\nStart: cleaning dnf metadata\nFinish: cleaning dnf metadata\nINFO: enabled HW Info plugin\nMock Version: 1.4.10\nINFO: Mock Version: 1.4.10\nFinish: chroot init\nINFO: installing package(s): /home/bothner/tmp/pgcli-1.9.1-3.fc28.src.rpm /home/bothner/tmp/python3-pgspecial-1.11.0-4.fc28.noarch.rpm\nERROR: Command failed: \n # /usr/bin/dnf --installroot /var/lib/mock/fedora-rawhide-x86_64/root/ --releasever 29 --disableplugin=local --setopt=deltarpm=False install /home/bothner/tmp/pgcli-1.9.1-3.fc28.src.rpm /home/bothner/tmp/python3-pgspecial-1.11.0-4.fc28.noarch.rpm\n\n' (logs in /home/bothner/.cache/fedora-review.log)

Or more readably, it looks like this command failed with return code 30:

# /usr/bin/dnf --installroot /var/lib/mock/fedora-rawhide-x86_64/root/ --releasever 29 --disableplugin=local --setopt=deltarpm=False install /home/bothner/tmp/pgcli-1.9.1-3.fc28.src.rpm /home/bothner/tmp/python3-pgspecial-1.11.0-4.fc28.noarch.rpm

Run the command separatly, it will tell you why it's failing. Probably a missing dep.

*** This bug has been marked as a duplicate of bug 1833785 ***