Improve the formatting of the preamble

[joerick]

The preamble has been getting a bit scruffy lately, this tidies it up.

• fixed the issue with environment thinking it was overridden when it wasn't
• objects like BuildSelector provide a custom, nested output, which is more friendly than the repr
• overrides are grouped when they have the same value
• using str rather than repr for other objects, makes e.g. Paths easier to read
• options that are set to their defaults are dimmed using an ANSI code

Simple example

Here I'm setting CIBW_ENVIRONMENT="a=1 b=2" CIBW_PLATFORM=linux

Before

After

more complicated example

This example has a pyproject.toml:

[tool.cibuildwheel]
build = ["cp38*", "cp37*"]
skip = ["*musllinux*"]
environment = {FOO="BAR"}

test-command = "pyproject"

manylinux-x86_64-image = "manylinux1"

environment-pass = ["EXAMPLE_ENV"]

[tool.cibuildwheel.macos]
test-requires = "else"

[[tool.cibuildwheel.overrides]]
select = "cp37*"
test-command = "pyproject-override"
manylinux-x86_64-image = "manylinux2014"

Before

After

---

At a code level, worth noting is that the Options object is passed in an environ object, rather than reading it from os.environ. This allows us to construct a 'default' Options object to compare with. Also, it requires less monkey-patching to test, which is nice.

[joerick]

ANSI 'gray' (\033[90m aka 'bright black') doesn't look good on github mobile for some reason, i guess it's just interpreted as 'black'. I'll try a mid-gray from the 256-color palette instead.

[joerick]

Github actions on web appears to forget the current ANSI color on newline. I'll need to refresh the color on each newline.

[henryiii]

Looks nice, a few minor nit picks / comments that you can ignore or address at your discretion. :)

[henryiii]

This is weird - though I see how it could happen, GH does a lot of optimization for logs. Is there a GH ticket or commend anywhere? I've not generally noticed GH breaking elsewhere with color, but maybe most things like compilers and pytest do per-line coloring too.

[joerick]

There is not. I should raise an issue somewhere. Not sure where though. Maybe I'll just raise it at actions/runner and see what they say.

[joerick]

Raised an issue here: https://github.com/orgs/community/discussions/40864