Some config doesn't work when loaded via --config-file

[teatwig]

Description

It seems like some config such as aliases and ui.default-command don't work if they're loaded via --config-file, but do work if they're specified in the regular config file.

Other options like

[colors]
working_copy = { bold = false }

work without issues.

Steps to Reproduce the Problem

1. Create a new file jjconfig2.toml with the following contents:

[aliases]
l = ["log"]

1. Run jj --config-file=jjconfig2.toml l

Expected Behavior

The log is displayed.

Actual Behavior

error: unrecognized subcommand 'l'

Specifications

• Platform: Linux
• Version: 0.25.0

[yuja]

Since aliases have to be expanded before parsing arguments, they cannot be defined by --config-file/--config args. Best we can do here is to show warning if --config-file would affect the expanded command.

[teatwig]

That makes sense and explains why it's only those options.

Maybe some background of why I'm trying to do this:

With git I'm always using two config files:

1. My shared config file in ~/.config/git/config that's synced between all machines
2. My machine specific config file in ~/.gitconfig (which can easily be changed with the CLI since it's the default)

Since jj doesn't allow both ~/.jjconfig.toml and ~/.config/jj/config.toml to exist at the same time I created an alias that always loads the shared config file as well.

For now I could probably just switch the files (since not being able to set them via the CLI is not a super big deal), but it would be nice if there was some kind of include mechanism that also supports alias expansion.

[yuja]

See #4926 (comment) for the multiple config files issue. Maybe we can change the default to ~/.config/jj/*.toml, but for now, you'll need to set JJ_CONFIG= env.

[teatwig]

Thank you! That works well enough for me.