Starting With Haunt

Last updated on 2025-06-27 | Edit this page

Estimated time: 30 minutes

Overview

Questions

  • “How can I create a static website with Haunt?”
  • “How can I configure values/settings for my site?”

Objectives

  • “Substitute variable values into page content”
  • “Adjust the configuration of the site and individual pages”

Haunt is a powerful static site generator. It creates static HTML website content out of various files in your repository (Skribe files, Markdown files, CSS style sheets, layouts, etc.). This ‘compiled’ content can then be served as your website via the github.io Web domain (remember your website’s URL from the previous episode?). Your GitHub repository can be configured to re-generate all the HTML pages for your website each time you make a change in it.

Haunt makes managing your website easier because it depends on templates. Templates are blueprints that can be reused by multiple pages. For example, instead of repeating the same navigation markup on every page you create (such a header, a footer or a top navigation bar), you can create a layout that gets used on all the pages. Otherwise, each time you update a navigation item - you’d have to make edits on every page. We will cover templates and layouts in a bit; for now let’s start learning Haunt and its scripting language called Scheme.

A first site

To create a Haunt site, fork the repository https://github.com/bkmgit/haunt-site and give it the name https://github.com/my-username.github.io Be sure to copy all branches of the repository.

Then go to settings, and choose to serve the site from the gh-pages branch and from the root folder.

The website should be rebuilt whenever there are changes to the repository. GitHub has a service called GitHub Actions. On the settings page, expand the Actions submenu and choose the General page. Ensure that - Allow all actions and reusable workflows - Require approval for first-time contributors = Read and write permissions are selected. The save your settings. For more on GitHub Actions settings, see the documentation.

Global Configuration

Haunt’s main configuration options are specified in a haunt.scm file, which is written in called Scheme and placed in your site’s root directory.

The initial global configuration contains

SCHEME 

(use-modules (haunt asset)
             (haunt page)
             (haunt builder blog)
             (haunt builder atom)
             (haunt builder assets)
	     (haunt builder flat-pages)
             (haunt builder redirects)
             (haunt builder rss)
	     (haunt reader)
             (haunt reader skribe)
             (haunt reader texinfo)
             (haunt reader commonmark)
             (haunt site))

(site #:title "Built with Haunt, a Scheme Static Site generator"
      #:domain "bkmgit.github.io"
      #:build-directory "docs"
      #:default-metadata
      '((author . "A.N. Other")
        (email  . "ano@contact.me"))
      #:readers (list commonmark-reader texinfo-reader skribe-reader sxml-reader html-reader)
      #:builders (list (blog)
                       (atom-feed)
                       (atom-feeds-by-tag)
                       (rss-feed)
                       (static-directory "images")))

Let’s modify the parameters for our website.

  1. From the GitHub interface, click on the haunt.scm file in your site’s root directory.
  2. Click on the pencil icon to edit the haunt.scm file.
  3. Update the author to your name and domain to myusername.github.io
  4. Optionally update the email or remove it if you do not wish to share your email address.
  5. Commit your changes.

A first change

Go to the code section of the repository, then view the posts folder and click on my-first-post.skr which should contain

SCHEME 

(post
 :title "My first post!"
 :date (make-date* 2025 06 21 09 00)
 :tags '("Skribe" "scheme" "program")

(h1 [My first post!])

(p [This is a static website and blog.])

(p [The source is written in Skribe, a
    document format that allows you to use
    embed scheme programs to create your
    document.])

(p [1 + 2 + 3 + 4 + 5 = ]
   (+ 1 2 3 4 5)))

The post contains some metadata including the title and date as well as tags to be used to indicate the topics of interest. It is written in Skribe. Text is enclosed in square brackets [] and code and annotations are enclosed in parenthesis (). The tag h1 indicates a first level heading and the tag p indicates a paragraph.

The third paragraph is unusual, there is a string [1 + 2 + 3 + 4 + 5 =] in square brackets followed by an expression (+ 1 2 3 4 5) in parenthesis. The expression is evaluated when generating the website.

Go to your website which should be avilable at https://my-username.github.io there should be a page with a link to your first blog post. Click on the link to open the first blog post. The last line should have 1 + 2 + 3 + 4 + 5 = 14.

Challenge: Modify the expression to be evaluated

In my-first-post.skr modify

SCHEME 

(p [1 + 2 + 3 + 4 + 5 = ]
   (+ 1 2 3 4 5)))

to add numbers from 1 to 7. Commit your changes, then wait for the site to be regenerated. Confirm that the correct sum is shown.

  1. Modify the last section of my-first-post.skr to contain

SCHEME 

(p [1 + 2 + 3 + 4 + 5 + 6 + 7= ]
   (+ 1 2 3 4 5 6 7)))

When Things Go Wrong

So far we have seen how to successfully use Haunt to produce a website. There are however some situations where Haunt may fail to do so either due to a typo or missing information.

Challenge: Troubleshooting Haunt

This exercise will help you recognise what common mistakes look like when working with these elements of a Haunt website.

Edit your haunt.scm file and omit a closing parenthesis ) in one of the lists.

For instance, a missing closing parenthesis ) after blog in the site section.

SCHEME 

(use-modules (haunt asset)
             (haunt page)
             (haunt builder blog)
             (haunt builder atom)
             (haunt builder assets)
	     (haunt builder flat-pages)
             (haunt builder redirects)
             (haunt builder rss)
	     (haunt reader)
             (haunt reader skribe)
             (haunt reader texinfo)
             (haunt reader commonmark)
             (haunt site))

(site #:title "Built with Haunt, a Scheme Static Site generator"
      #:domain "bkmgit.github.io"
      #:build-directory "docs"
      #:default-metadata
      '((author . "A.N. Other")
        (email  . "ano@contact.me"))
      #:readers (list commonmark-reader texinfo-reader skribe-reader sxml-reader html-reader)
      #:builders (list (blog
                       (atom-feed)
                       (atom-feeds-by-tag)
                       (rss-feed)
                       (static-directory "images")))

Haunt will refuse to build the website and produce an error message.

We will see after this where to find the error message and identify what caused them.

If you were keeping an eye on the GitHub repository page until now, you may have noticed a yellow circle visible when the website is still being processed and a green check mark (✓) when successful. You may have also noticed that in the same location there is now a red cross/X next to the commit message (❌). This indicates that something went wrong with the Haunt build process after that commit.

Jekyll pending/successful/failed builds after different commits
Jekyll pending/successful/failed builds after different commits

You may also find an email from GitHub in your inbox with details about the error. But let’s look at our repository again. If we click the red cross/X next to the commit message (❌) a little pop-up will appear with additional information.

Jekyll - a failed build
Jekyll - a failed build

Visiting the page behind the Details link will give us the information we were missing.

Jekyll - error details of a failed build
Jekyll - error details of a failed build

The build should contain output with some content similar to

OUTPUT 

ice-9/read.scm:126:4: In procedure lp:
haunt.scm:27:1: unexpected end of input while searching for: )

From this page we can see that what caused the failure affected the haunt.scm file, and we should check for a missing parenthesis. Since this typo prevents Haunt from building the page, the process cannot continue.

Failure Will Not Remove Your Website

Given the failure you may be wondering what happened to the website? If you visit the address you will find that the website is still be available.

GitHub will keep your previous version online until the error is fixed and a new build is completed successfully.

Lets go ahead and fix your intentional typo and re-add the missing ):

SCHEME 

(use-modules (haunt asset)
             (haunt page)
             (haunt builder blog)
             (haunt builder atom)
             (haunt builder assets)
	     (haunt builder flat-pages)
             (haunt builder redirects)
             (haunt builder rss)
	     (haunt reader)
             (haunt reader skribe)
             (haunt reader texinfo)
             (haunt reader commonmark)
             (haunt site))

(site #:title "Built with Haunt, a Scheme Static Site generator"
      #:domain "bkmgit.github.io"
      #:build-directory "docs"
      #:default-metadata
      '((author . "A.N. Other")
        (email  . "ano@contact.me"))
      #:readers (list commonmark-reader texinfo-reader skribe-reader sxml-reader html-reader)
      #:builders (list (blog)
                       (atom-feed)
                       (atom-feeds-by-tag)
                       (rss-feed)
                       (static-directory "images")))

After a few seconds we should see a green checkmark again and our website will be updated.

Challenge: Practice With Troubleshooting

Sometimes typos happen and can make your website change in surprising ways. Let’s experiment with some possible issues that might come up and see what happens.

Try the changes listed below on your my-first-post.skr file and see what happens when you try to build the site. You will want to correct the previous mistake each time.

  1. Remove an opening square bracket [.
  2. Remove a closing square bracket ].
  3. Change :tags '( to :tags (.
  4. Change :date to date.
  5. Change (p [The source to ( [The source.
  1. The site refuses to build and the build logs have an error message.

OUTPUT 

ERROR: In procedure %resolve-variable:
Unbound variable: #{\x5d;}#
  1. The site builds, butwhen viewed in a browser a section is extended. Example generated html is below.

HTML 

<!DOCTYPE html><head><meta charset="utf-8" /><title>My first post! — Built with Haunt, a Scheme Static Site generator</title></head><body><h1>Built with Haunt, a Scheme Static Site generator</h1><h2>My first post!</h2><h3>by A.N. Other — Sat 21 June 2025</h3><div><h1>My first post!)

(p [This is a static website and blog.</h1><p>The source is written in Skribe, a
    document format that allows you to use
    embed scheme programs to create your
    document.</p><p>1 + 2 + 3 = 6</p></div></body>
  1. The site refuses to build with the output message

OUTPUT 

ice-9/eval.scm:217:33: In procedure lp:
Wrong type to apply: "Skribe"
  1. When the colon before date is removed the site refuses to build with the error message:

OUTPUT 

ERROR: In procedure %resolve-variable:
Unbound variable: date
  1. When the p annotation is removed the site refuses to build with the error message:

OUTPUT 

ice-9/eval.scm:217:33: In procedure lp:
Wrong type to apply: ("The source is written in Skribe, a\n    document format that allows you to use\n    embed scheme programs to create your\n    document.")

Challenge: Practice With Troubleshooting (continued)

Note: Be sure to fix any errors you intentionally introduced in your page before moving on.

Key Points

  • “Sites can be built by GitHub using GitHub Actions”
  • “Site build configuration is done in haunt.scm”
  • “Errors can happen but Haunt will often tell us something is wrong”