safe_yaml | popular open source library which contained code | YAML Processing library

I have "installed" bundler and jekyll without issue per the following trace:

I am trying to contribute to a Github Page/Jekyll site and want to be able to visualise changes locally but when I run bundle exec jekyll serve but I get this output:

I'm trying to revive an old Rails application I worked on several years ago. I'm using ruby 2.3.3 and rails 3.2.15 on the Heroku-16 stack with ClearDB for my MySQL database with the mysql2 adapter. When deploying to Heroku it succeeds on the deploy but crashes when it tries to start the app.

Full stack trace from the Heroku log (updated after fixing activerecord-import gem version per suggestion in first answer):

I tried to add the "Jekyll" workflow to my repository in Github, but every time it runs it is marked as failure.

Here is an error message, I tried to remove Gemfile.lock from exclude (_config.yml) but it didn't help... Here is a repository to which I'm trying to add a workflow: https://github.com/igorkowalczyk/blog

I tried to create a website using Jekyll.

I used git clone to copy jekyll-theme-hackcss, and then followed instructions from the arch-wiki rubygems page to get the right gem packages.

From inside the cloned folder I used:

I picked up a 4 year old project written in Ruby 2.1.3 and Rails 4.1.8.

Very few of the gems were versioned but I've managed to get the project running locally by installing mysql2 0.3.20 as suggested in multiple other threads. Doing this required me to (on MacOS) downgrade openssl and mysql with brew install mysql@57 and brew install openssl@10.

I could then install mysql2 with by passing the correct libraries to it: gem install mysql2 -v 0.3.20 -- --with-mysql-config=/usr/local/opt/mysql@5.7/bin/mysql_config --with-ldflags=-L/usr/local/opt/openssl@1.0/lib --with-cppflags=-I/usr/local/opt/openssl@1.0/include

Everything works locally, all good.

I'm trying to deploy this project with Dokku on a Debian instance. Here's the readout from the push to dokku master including the error thrown when starting the Rails server:

First of all, I'm aware that I'm running the risk that this question is already answered somewhere else, but because I don't know the origin of this issue I'm not sure what to search for to find the answer.

The Problem

I'm running bundle and Jekyll locally, which works perfectly fine. But when I install on Travis-CI, it presents me with the error Could not find public_suffix-4.0.4 in any of the sources. However, public_suffix-4.0.4 is clearly in my Gemfile.lock.

My Question

What might be causing the problem and what hints should I look for to find an answer?

Error message

I have a Rails import job that run as a cron job setup through the whenever gem. It was running correctly until I recently updated the app. Now we are seeing the following Error in the logs when the cron job tries to run. If I run the task manually it runs the import correctly.