I tested this build and it seems like opam init still fails due to missing gcc:

$ sudo docker run -it --rm registry.fedoraproject.org/fedora:27 /bin/bash      
[root@5e2c5f620587 /]# dnf install --enablerepo updates-testing opam && opam init
<snip>
Installing:                                  
 opam                    x86_64          2.0.0-0.8.beta6.fc27             updates-testing          1.9 M
<snip>
[WARNING] Running as root is not recommended                                                             
[NOTE] Will configure from built-in defaults.
Checking for available remotes: none.                                                                   
  - you won't be able to use rsync and local repositories unless you install the rsync command on your
    system.                                                                                             
  - you won't be able to use git repositories unless you install the git command on your system.                                                                                                                  
  - you won't be able to use mercurial repositories unless you install the hg command on your system.   
  - you won't be able to use darcs repositories unless you install the darcs command on your system.    

[WARNING] Recommended dependencies -- most packages rely on these:
            - make                
            - m4                                                                                         
            - cc                                     


=-=- Fetching repository information =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
[default] Initialised                         


=-=- Required setup - please read -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=                    

  In normal operation, opam only alters files within ~/.opam.                                       

  However, to best integrate with your system, some environment variables                           
  should be set. If you allow it to, this initialisation step will update                                
  your sh configuration by adding the following line to ~/.profile:                                 

    test -r /root/.opam/opam-init/init.sh && . /root/.opam/opam-init/init.sh > /dev/null 2> /dev/null || true

  Otherwise, every time you want to access your opam installation, you will
  need to run:                

    eval $(opam env)                                                                                    

  You can always re-run this setup with 'opam init' later.
Do you want opam to modify ~/.profile ? [N/y/f]
(default is 'no', use 'f' to choose a different file)


=-=- Creating initial switch (ocaml-base-compiler) =-=-=-=-=-=-=-=-=-=-=-=-=-=-=

=-=- Gathering sources =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
[ocaml-base-compiler.4.07.0] downloaded from cache at https://opam.ocaml.org/cache

=-=- Processing actions -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
-> installed base-bigarray.base
-> installed base-threads.base
-> installed base-unix.base
[ERROR] The compilation of ocaml-base-compiler failed at
        "/root/.opam/default/.opam-switch/build/ocaml-base-compiler.4.07.0/./configure -prefix
        /root/.opam/default -with-debug-runtime".

#=== ERROR while compiling ocaml-base-compiler.4.07.0 =========================#
# context      2.0.0~beta6 | linux/x86_64 |  | https://opam.ocaml.org#bdce7d8b
# path         ~/.opam/default/.opam-switch/build/ocaml-base-compiler.4.07.0
# command      ~/.opam/default/.opam-switch/build/ocaml-base-compiler.4.07.0/./configure -prefix /root/.opam/default -with-debug-runtime                                                                          
# exit-code    2
# env-file     /tmp/opam-xxx-42/ocaml-base-compiler-42-2c871f.env
# output-file  /tmp/opam-xxx-42/ocaml-base-compiler-42-2c871f.out
### output ###
# Configuring OCaml version 4.07.0
# Configuring for host x86_64-unknown-linux-gnu ...
# Configuring for target x86_64-unknown-linux-gnu ...
# Using compiler cc.
# /root/.opam/default/.opam-switch/build/ocaml-base-compiler.4.07.0/./configure: line 401: cc: command not found                                                                                                  
# Compiler family and version: .
# [ERROR!] Unable to compile the test program.
#  Make sure the C compiler cc is properly installed.



=-=- Error report -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
+- The following actions were aborted
| - install ocaml 4.07.0
+- 
+- The following actions failed
| - build ocaml-base-compiler 4.07.0
+- 
+- The following changes have been performed
| - install base-bigarray base
| - install base-threads  base
| - install base-unix     base
+- 
# Run eval $(opam env) to update the current shell environment
Switch initialisation failed, clean up ? ('n' will leave the switch partially installed) [Y/n] y

Indeed, if I remove pyPdf, pdfshuffler will not start:

$ sudo dnf remove pyPdf
Dependencies resolved.
======================================================================================================================
 Package                  Arch                      Version                         Repository                   Size
======================================================================================================================
Removing:
 pyPdf                    noarch                    1.13-15.fc28                    @rawhide                    317 k

Transaction Summary
======================================================================================================================
Remove  1 Package

Freed space: 317 k
Is this ok [y/N]: y
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
  Preparing        :                                                                                              1/1 
  Erasing          : pyPdf-1.13-15.fc28.noarch                                                                    1/1 
  Running scriptlet: pyPdf-1.13-15.fc28.noarch                                                                    1/1 
  Verifying        : pyPdf-1.13-15.fc28.noarch                                                                    1/1 

Removed:
  pyPdf.noarch 1.13-15.fc28                                                                                           

Complete!
$ pdfshuffler 
Error: Could not import pdfshuffler
Cause: No module named pyPdf

python-blivet-3.1.0-2.fc29 has been removed from this update.

I was able to renew a certificate on my mail server with this.

I installed this on my Ampache server and it seems to work still.

This seems to work on my web server.

My web server seems to work with this update installed.

Seems to work on my web server.

My web server boots and serves the entire web with this update installed.

My web server seems to work with this update installed.

My web server seems to boot with this update installed.

I tested this on my web server and it seems to work.

I tested this on my web server and it seems to work.

I installed this on a Gnome VM and its network still seems to function.

I tested this by editing a PDF that had wrongly rotated pages and fixing them. Seemed to work just fine.

I installed this on my database VM and it seems to answer queries still.

I installed this on my development server and my VMs seem to work.

I installed this on my Nextcloud server and it seems to work.

I tested this with my music server and it seems to work.

I tested this on an x86_64 libvirt guest and it seemed to work. I had not been observing the referenced crash so I can't comment about it.