tomholford

Email Styling Best Practices

Email rendering is fundamentally different from web rendering. There is no universal standard — each email client uses its own engine, strips different things, and handles dark mode differently. This guide is split into two parts: design principles for designers, and technical reference for developers.

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Part 1: Design Principles

For designers who may not be familiar with email-specific constraints.

tomholford

Fixing rclone Proton Drive Uploads (March 2026)

Proton Drive uploads via rclone have been broken since ~November 2025. This documents the root causes, fixes, and testing.

Problem

Three issues combine to break uploads:

1. Missing block verification tokens — Proton's storage backend now requires a Verifier.Token per block in POST /drive/blocks. Without it, every block upload fails with 422 / Code=200501. This is the primary cause.
2. Broken shouldRetry() — backend/protondrive/protondrive.go:248 always returns (false, err), disabling rclone's pacer retry logic entirely.

tomholford

Git Branch Cleanup Aliases for Zsh

Improved one-liners for cleaning up stale local branches after merge. Inspired by the CIA's leaked dev docs and HN discussion.

Helpers

# Auto-detect default branch (main/master) from remote
function _git_default_branch() {
  git symbolic-ref refs/remotes/origin/HEAD 2>/dev/null | sed 's@^refs/remotes/origin/@@' || echo "main"

tomholford

Installing pg gem on macOS

If you're trying to install the postgresql gem pg and it is failing with the following error message:

Installing pg 1.2.3 with native extensions
Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

    current directory: ~/.rbenv/versions/3.0.0/lib/ruby/gems/3.0.0/gems/pg-1.2.3/ext
~/.rbenv/versions/3.0.0/bin/ruby -I ~/.rbenv/versions/3.0.0/lib/ruby/3.0.0 -r ./siteconf20210125-97201-pycpo.rb extconf.rb

tomholford

extends

An elegant way to nest Rails layouts.

Example Usage

# devise.html.erb
<%= extends :application do %>
 

tomholford

curl https://thispersondoesnotexist.com/image -o ~/$(date +%s).jpg

tomholford

1. Add the following to app/helpers/application_helper.rb:

  def external_link_to(name = nil, options = nil, html_options = nil, &block)
    opts = { target: '_blank', rel: 'nofollow noopener' }
    if block_given?
      options ||= {}
      options = options.merge(opts)
    else
      html_options ||= {}
 html_options = html_options.merge(opts)

tomholford

f = proc do |p|
  Hash.new.merge(
   ->{ p.odd? }.call => 'odd',
   ->{ p.even? }.call => 'even'
  ).fetch(true)
end
=> #<Proc:0x00007ff91188af38@(irb):1>

> f[1]
=> "odd"