Cannot install Jekyll after updating to Catalina - An error occurred while installing ffi (1.9.18)

I have updated my mac to use Catalina and now I am having all sorts of issues when I try and install Jekyll.

This is what I get when I run my usual grunt setup:

Running "jekyll:dist" (jekyll) task
>> Error: Command failed: bundle exec jekyll -v
>> bundler: command not found: jekyll
>> Install missing gem executables with `bundle install`
Warning: Please install Jekyll before running this task. Use --force to continue.

I then run sudo bundle install

I then get this:

Don't run Bundler as root. Bundler can ask for sudo if it is needed, and installing your bundle as root will break this
application for all non-root users on this machine.
Fetching gem metadata from https://rubygems.org/.........
Using public_suffix 3.0.1
Using addressable 2.5.2
Using bundler 2.1.4
Using colorator 1.1.0
Fetching ffi 1.9.18
Installing ffi 1.9.18 with native extensions
Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

    current directory: /Applications/MAMP/htdocs/hangr/vendor/bundle/ruby/2.6.0/gems/ffi-1.9.18/ext/ffi_c
/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/bin/ruby -I
/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0 -r ./siteconf20201016-30905-1yh2cx1.rb extconf.rb
checking for ffi_call() in -lffi... yes
checking for ffi_prep_closure()... yes
checking for ffi_raw_call()... yes
checking for ffi_prep_raw_closure()... yes
checking for shlwapi.h... no
checking for rb_thread_blocking_region()... no
checking for rb_thread_call_with_gvl()... yes
checking for rb_thread_call_without_gvl()... yes
checking for ffi_prep_cif_var()... yes
creating extconf.h
creating Makefile

current directory: /Applications/MAMP/htdocs/hangr/vendor/bundle/ruby/2.6.0/gems/ffi-1.9.18/ext/ffi_c
make "DESTDIR=" clean

current directory: /Applications/MAMP/htdocs/hangr/vendor/bundle/ruby/2.6.0/gems/ffi-1.9.18/ext/ffi_c
make "DESTDIR="
compiling AbstractMemory.c
compiling ArrayType.c
compiling Buffer.c
compiling Call.c
Call.c:355:5: error: implicit declaration of function 'rb_thread_call_without_gvl' is invalid in C99
[-Werror,-Wimplicit-function-declaration]
    rbffi_thread_blocking_region(call_blocking_function, data, (void *) -1, NULL);
    ^
./Thread.h:78:39: note: expanded from macro 'rbffi_thread_blocking_region'
# define rbffi_thread_blocking_region rb_thread_call_without_gvl
                                      ^
1 error generated.
make: *** [Call.o] Error 1

make failed, exit code 2

Gem files will remain installed in /Applications/MAMP/htdocs/hangr/vendor/bundle/ruby/2.6.0/gems/ffi-1.9.18 for inspection.
Results logged to
/Applications/MAMP/htdocs/hangr/vendor/bundle/ruby/2.6.0/extensions/universal-darwin-19/2.6.0/ffi-1.9.18/gem_make.out

An error occurred while installing ffi (1.9.18), and Bundler cannot continue.
Make sure that `gem install ffi -v '1.9.18' --source 'https://rubygems.org/'` succeeds before bundling.

In Gemfile:
  jekyll was resolved to 3.4.3, which depends on
    jekyll-sass-converter was resolved to 1.5.1, which depends on
      sass was resolved to 3.5.5, which depends on
        sass-listen was resolved to 4.0.0, which depends on
          rb-inotify was resolved to 0.9.10, which depends on
            ffi

When I run

ruby -v

I get

ruby 2.6.3p62 (2019-04-16 revision 67580) [universal.x86_64-darwin19]

I have no idea at all what I need to do.

When I run

jekyll -v

I get

-bash: /usr/local/bin/jekyll: /System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/bin/ruby: bad interpreter: No such file or directory

I tried running this from another post but had no luck gem install ffi -v '1.9.18' -- --with-cflags="-Wno-error=implicit-function-declaration"

Does anyone have any ideas?

Thanks

Solution

The root problem is that you cannot install one of jekyl's dependancies - specifically the ffi gem. Knowing that will better help you workout a fix.

You can see that this is the error by reading your bundle output. Learn how to read these so you can better help yourself in the future; If you were searching for "install ffi on macOS" you might have found more information available to you.

Give that you've just installed Catalina, it's likely that GCC isn't on your machine, or is outdated, or is unlinked.

Try running xcode-select --install to (re)install the Xcode command line tools.

ALSO - STOP USING SUDO

At the very top of your bundle output is a warning that you shouldn't use sudo when installing gems. It's good advice to follow!

Even better advice would be to use rbenv or rvm to create gem sets or environments for each ruby application you're working with. But, if you don't go all the way down that path, ** at least, stop using sudo**