Include git output when commands fail

[technicalpickles]

⚡ Summary

Sometimes there are failures coming from git, but the output isn't shown so it is very hard to start debugging. LEFTHOOK_VERBOSE=1 can help, but I think it'd be better for users to have more context up front

Value

Lefthook git-related failures will be easier to debug. Having an more specific error will help people find/file reports

Behavior and configuration changes

Here's the current behavior:

Here's the behavior with LEFTHOOK_VERBOSE=1:

Not sure exactly what the output should look like, but some quick initial thoughts:

[lefthook] Couldn't restore hidden unstaged files: git had exit code 1
cmd: [git apply -v --whitespace=nowarn --recount --unidiff-zero .git/info/lefthook-unstaged.patch]
out: Checking patch lua/plugins/editor.lua...
error: while searching for:
        opts = {
        },

error: patch failed: lua/plugins/editor.lua:122
error: lua/plugins/editor.lua: patch does not apply
Checking patch lua/plugins/lsp.lua...
Checking patch lua/plugins/telescope.lua...
error: while searching for:
                function ()

error: patch failed: lua/plugins/telescope.lua:238
error: lua/plugins/telescope.lua: patch does not apply

[doniz]

It's out of scope and I believe it's really necessary to have a context why that happened. However, I got the same issue one hour ago, how unexpectedly that happened 😄 But in my case I solved this by adding stage_fixed

Used only for pre-commit hook. Is ignored for other hooks.
When set to true lefthook will automatically call git add on files after running the command or script.