Changing (sha256 .Title) changed {{ if eq .RelPermalink "/" }}…once

I think I’ve stumbled over a heisenbug. I don’t think I can reproduce it reliably anymore, but I wanted to mention it in case it helps point to some sort of funny business somewhere.

I have a bunch of colored breadcrumbs across the top of my website. Each breadcrumb is supposed to have its own color based on a hash of something about the page. However, the leftmost breadcrumb — to the home page — is supposed to be a special color and special label; that’s what the {{ if eq .RelPermalink "/" }} clause is for.

The googly.html partial expands to something like <a href='{{.Get "href" }} title='…'><svg>…</svg></a>.

I usually do local development with hugo serve -w. As I was changing the .Title of (sha256 .Title) to other things like .URL and .Permalink, I noticed that the leftmost breadcrumb didn’t have its special color. Instead, it had some other color that was most likely generated from the (first 6 (sha256 .Permalink)) expression. After refreshing the page and restarting Hugo and refreshing the page, the leftmost breadcrumb had the right color, but I didn’t expect to have to go through all that trouble to, what seems to me, make {{ if eq .RelPermalink "/" }} evaluate properly all the time.

<nav class='googly-navigation googly-navigation-top googly-navigation-left'>
    {{ template "section-nav" . }}

{{ define "section-nav" }}
    {{ if .Parent }}
        {{ template "section-nav" .Parent }}
    {{ else if (eq .Section "blog") }}
        {{ range where .Site.Pages "RelPermalink" "/blog/"}}
            {{ template "section-nav" . }}
        {{ end }}

    {{ end }}

    {{ $.Scratch.Set "href" .RelPermalink }}
    {{ $.Scratch.Set "title" .Title }}
    {{ $.Scratch.Set "color" (first 6 (sha256 .Permalink))  }}
    {{ if eq .RelPermalink "/" }}
        {{ $.Scratch.Set "color" "5fb5b4" }}
        {{ $.Scratch.Set "title" "Home Page" }}
    {{ end }}
    {{ partial "googly.html" $.Scratch }}
{{ end }}

On a semi-related note, would it help anyone else here if hugo serve sent “don’t cache, redownload everything” headers? Or would that just paper over deeper issues?