feat(set): add -E/--env flag to mise set command

[jdx]

Summary

• Adds the -E/--env flag to the mise set command for creating environment-specific config files
• Allows users to create files like mise.staging.toml instead of modifying the main mise.toml
• Implements the same pattern used by mise use --env

Problem

When using mise set -E to set an environment, if a .mise.toml file already exists, the command did not create the expected environment file (e.g., .mise.pp.toml). Instead, it would modify the existing .mise.toml file.

Fixes: #5046

Changes

• Added -E/--env flag to Set struct with proper clap attributes and conflict resolution
• Updated filename() method to handle environment-specific config file paths
• Added comprehensive e2e test (test_set_env) to verify functionality
• Updated help documentation with usage examples

Test plan

• Created e2e test that reproduces the original issue and verifies the fix
• Verified existing mise set functionality still works
• Verified existing mise use --env functionality still works
• Manual testing of the new -E flag
• Linting and formatting checks pass

🤖 Generated with Claude Code

[Copilot]

Pull Request Overview

This PR adds support for environment-specific configuration files to the mise set command by implementing the -E/--env flag. This allows users to create or modify environment-specific config files like mise.staging.toml instead of always modifying the main mise.toml file.

• Added -E/--env flag to the mise set command for environment-specific configurations
• Updated the filename resolution logic to handle environment-specific config file paths
• Added comprehensive end-to-end test to verify the new functionality

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
src/cli/set.rs	Added -E/--env flag support and updated filename resolution logic for environment-specific config files
e2e/cli/test_set_env	New end-to-end test to verify the -E flag creates environment-specific config files

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[Copilot]

Using unwrap_or_default() on current_dir() will silently fail and return an empty PathBuf if the current directory cannot be determined. This could lead to unexpected behavior when trying to create config files. Consider propagating the error or using a more explicit fallback strategy.

[Copilot]

[nitpick] The string formatting is duplicated in both branches. Consider extracting the filename generation into a helper function or storing the formatted strings in variables to reduce duplication and improve maintainability.

Suggested change

	let p = cwd.join(format!(".mise.{env}.toml"));
	if p.exists() {
	p
	} else {
	cwd.join(format!("mise.{env}.toml"))
	let make_env_filename = |env: &str, dotted: bool| {
	if dotted {
	format!(".mise.{env}.toml")
	} else {
	format!("mise.{env}.toml")
	}
	};
	let p = cwd.join(make_env_filename(env, true));
	if p.exists() {
	p
	} else {
	cwd.join(make_env_filename(env, false))

[github-actions]

Hyperfine Performance

mise x -- echo

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
mise-2025.9.10 x -- echo	19.1 ± 0.2	18.7	21.5	1.00
mise x -- echo	19.2 ± 0.2	18.7	20.4	1.00 ± 0.02

mise env

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
mise-2025.9.10 env	18.5 ± 0.3	17.9	21.5	1.00
mise env	18.7 ± 0.5	18.1	24.2	1.01 ± 0.03

mise hook-env

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
mise-2025.9.10 hook-env	18.2 ± 0.6	17.7	24.9	1.00
mise hook-env	18.3 ± 0.4	17.8	25.4	1.00 ± 0.04

mise ls

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
mise-2025.9.10 ls	16.0 ± 0.2	15.6	17.4	1.00
mise ls	16.1 ± 0.2	15.6	17.2	1.00 ± 0.02

xtasks/test/perf

Command	mise-2025.9.10	mise	Variance
install (cached)	165ms	✅ 101ms	+63%
ls (cached)	62ms	62ms	+0%
bin-paths (cached)	68ms	68ms	+0%
task-ls (cached)	477ms	477ms	+0%

✅ Performance improvement: install cached is 63%