middleman: "uninitialized constant Haml::Options" error while launching Middleman server on a fresh install

I tried creating a fresh new Middleman project and launching the server.

$ gem install middleman
$ mkdir project
$ middleman init
$ middleman server

Command middleman server fails to launch giving the following error message:

/Users/username/.rvm/gems/ruby-3.1.2/gems/middleman-core-4.4.2/lib/middleman-core/renderers/haml.rb:49:in `initialize': uninitialized constant Haml::Options (NameError)

::Haml::Options.defaults[:context] = nil

I’m also getting the same error message this way.

$ gem install middleman
$ middleman init project

Additional information

Ruby version: 3.1.2 installed via RVM
Middleman version: 4.2.2
OS version: macOS 12.5

About this issue

Original URL
State: closed
Created 2 years ago
Comments: 15 (8 by maintainers)

Commits related to this issue

Lock haml to < 6.0 6.0 introduces breaking changes (see #2569) — committed to zofrex/middleman by zofrex 2 years ago
Lock haml to < 6.0 6.0 introduces breaking changes (see #2569) — committed to zofrex/middleman by zofrex 2 years ago
Lock haml to < 6.0 (#2570) 6.0 introduces breaking changes (see #2569) — committed to middleman/middleman by zofrex 2 years ago
Fix issue with haml version https://github.com/middleman/middleman/issues/2569 — committed to tim-vandecasteele/lauranne-paulissen by tim-vandecasteele 2 years ago
Revert "chore(deps): Bump haml from 5.2.2 to 6.0.3" This reverts commit 21d1e10a49e6a356316bf0b771246977b79ebafc. Because of incompatibility with middleman. https://github.com/middleman/middleman/is... — committed to qnyp/qnyp-company by deleted user 2 years ago
Upgrade bundle, using middleman from github to work around https://github.com/middleman/middleman/issues/2569 — committed to betesh/hebrewCalendar.js by betesh 2 years ago

Most upvoted comments

I also prepared a backport to the current 4.x branch https://github.com/middleman/middleman/pull/2590. Please consider merging (and releasing) it before or after the rename.

k0kubun on Nov 11, 2022

As a temporary workaround you can fix this in any project using a Gemfile by limiting the version of haml in your Gemfile, for example:

source "https://rubygems.org"

gem 'middleman', '~> 4.2'
gem 'middleman-autoprefixer'

# Temporary fix for https://github.com/middleman/middleman/issues/2569
gem 'haml', '~> 5.0'

zofrex on Sep 21, 2022

Published as v4.4.3 https://rubygems.org/gems/middleman/versions/4.4.3

tdreyno on Nov 9, 2022

Hello everyone 👋🏼 The fix was already merged (in both branches, 4.x and 5.x), but still not released, see:

In the meantime, you can point the gem to GitHub 4.x branch:

gem 'middleman', github: 'middleman', branch: '4.x'

Or if you are already using on 5.x:

gem 'middleman', github: 'middleman', branch: 'master'

markets on Oct 27, 2022

Same issue.

Ruby 3.1.2 installed via chruby
Middleman 4.4.2
macOS 12.6 (M1)

foxacid on Oct 17, 2022

Same as above - middleman init is throwing the same error for me

ntsim on Sep 26, 2022