Delta for diffs

[robinst]

I'm used to https://github.com/dandavison/delta for looking at diffs, and was wondering how to set it up with jj. I started with just setting the tool:

[ui.diff]
tool = "delta"

That results in this:

$ jj diff

Δ var/folders/jl/2lwh7cg533j2f03mnjk7vfv80000gn/T/jj-diff-plVolZ/left/docs/index.md ⟶   var/folders/jl/2lwh7cg533j2f03mnjk7vfv80000gn/T/jj-diff-plVolZ/right/docs/index.md
──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────

─────┐
• 1: │
─────┘
# Jujutsu—a version control system
# Jujutsu—a version control system test

## Welcome to `jj`'s documentation website!

Warning: Tool exited with exit status: 1 (run with --debug to see the exact invocation)

Note the very long left/right path. It can be improved like this:

[ui.diff]
tool = ["delta", "$left", "$right", "--file-transformation", "s|.*/jj-diff-[^/]*/[^/]*/||"]

$ jj diff

Δ docs/index.md ⟶   docs/index.md
────────────────────────────────────────────────────────────────────────────────

─────┐
• 1: │
─────┘
# Jujutsu—a version control system
# Jujutsu—a version control system test

## Welcome to `jj`'s documentation website!

Warning: Tool exited with exit status: 1 (run with --debug to see the exact invocation)

What I haven't found is how to silence the warning at the end:

Warning: Tool exited with exit status: 1 (run with --debug to see the exact invocation)

Has anyone figured out how? Any other tips?

[robinst]

Shortly after posting this, I found the section about pagers in the docs, and this makes jj diff work nicely:

[ui]
pager = "delta"

[ui.diff]
format = "git"

I'll leave this post up because I couldn't find how to configure delta before (and I searched through discussions).

One problem that's left is with the above config, jj log -p doesn't use the pager, but that seems to be a known issue:

• FR: jj log respect the diff pager config #4142