How to fix "extconf.rb:8:in `require': no such file to load -- mkmf (LoadError)"
If you're on Ubuntu:
sudo apt-get install ruby-dev
On other platforms: Look for a package containing ruby header files. On Red Hat that's "ruby-devel" likely.
Related cards:
Lightning Talk: Coverage based Test Case Prioritization in Ruby on Rails
For my computer science bachelor's thesis I programmed and evaluated a CLI Test Case Prioritization (TCP) tool for makandra. It has been written as a Ruby Gem and was tested and evaluated against one Ruby on Rails project....
The Ruby Object Model
In Ruby (almost) everything is an Object
. While this enables a lot of powerful features, this concept might be confusing for developers who have been programming in more static languages, such as Java or C#. This card should help understanding t...
How to create giant memory leaks in AngularJS (and other client-side JavaScript)
This guide shows how to create an AngularJS application that consumes more and more memory until, eventually, the browser process crashes on your users.
Although this guide has been written for Angular 1 originally, most of the advice is relevant...
How to: Upgrade CarrierWave to 3.x
While upgrading CarrierWave from version 0.11.x to 3.x, we encountered some very nasty fails. Below are the basic changes you need to perform and some behavior you may eventually run into when upgrading your application. This aims to save you some...
How to make changes to a Ruby gem (as a Rails developer)
At makandra, we've built a few gems over the years. Some of these are quite popular: spreewald (> 1M downloads), active_type (> 1M downloads), and geordi (> 200k downloads)
Developing a Ruby gem is different from developing Rails applications, w...
Fix „rvm no such file to load -- openssl“ or "rvm no such file to load -- zlib"
For example if you use rvm and get this message:
ERROR: Loading command: install (LoadError)
no such file to load -- zlib
ERROR: While executing gem ... (NameError)
uninitialized constant Gem::Commands::InstallCommand
...
Invoices: How to properly round and calculate totals
While it might seem trivial to implement an invoice that sums up items and shows net, gross and vat totals, it actually involves a lot of rules and caveats. It is very easy to create invoices where numbers don't add up and a few cents are missing....
Fix error: rails console No such file to load -- irb/encoding_aliases.rb (LoadError)
I got this error after upgrading Ruby from 2.4.5 to 2.6.4 when I opened the Rails console - rails server
still worked.
Running via Spring preloader in process 14679
Loading development environment (Rails 5.2.2.1)
Traceback (most recent call...
CarrierWave: Processing images with libvips
When you write your next CarrierWave uploader, consider processing your images with libvips instead of ImageMagick.
Reasons for libvips
There are several **upsi...
The JavaScript Object Model: Prototypes and properties
Speaker today is Henning Koch, Head of Development at makandra.
This talk will be in German with English slides.
Introduction
As web developers we work with JavaScript every day, even when our backend code uses anothe...