Fixup cli to handle parsing matches when called as a cargo subcommand

[dsteeley]

Fixes #118.
Expect this issue can be fixed in multiple ways and happy for an alternative to be suggested. The underlying issue is that we're not correctly parsing the argument matches when cargo-generate-rpm is called as a cargo subcommand.

To regain the previous behaviour the arguments of the generate-rpm subcommand need to be reparsed. The issue can be reproduced by running cargo run generate-rpm on the latest main.

thread 'main' panicked at src/cli.rs:134:40:
`"metadata_overwrite"` is not an id of an argument or a group.

[dsteeley]

Debug output of matches at the point of a panic. Demonstrating that the arguments of the subcommand generate-rpm need to be parsed to match the args of the Cli struct.

ArgMatches { 
valid_args: ["help"], 
valid_subcommands: ["generate-rpm", "help"], 
args: FlatMap { keys: [], values: [] }, 
subcommand: Some(SubCommand { 
  name: "generate-rpm", 
  matches: ArgMatches { 
    valid_args: ["arch", "output", "package", "auto_req", "target", "target_dir", "profile", "payload_compress", "source_date", "metadata_overwrite", "set_metadata", "variant", "help", "version", "Cli"], 
    valid_subcommands: [], 
    args: FlatMap { 
      keys: ["auto_req", "profile", "payload_compress"], 
      values: [MatchedArg { 
        source: Some(DefaultValue), indices: [1], type_id: Some(cargo_generate_rpm::cli::AutoReqMode), vals: [[AnyValue { inner: cargo_generate_rpm::cli::AutoReqMode }]], 
      raw_vals: [["auto"]], 
      ignore_case: false }, 
    MatchedArg { 
      source: Some(DefaultValue), 
      indices: [2], 
      type_id: Some(alloc::string::String), 
      vals: [[AnyValue { inner: alloc::string::String }]], 
      raw_vals: [["release"]], 
      ignore_case: false }, 
    MatchedArg { 
      source: Some(DefaultValue), 
      indices: [3], 
      type_id: Some(cargo_generate_rpm::cli::Compression), 
      vals: [[AnyValue { inner: cargo_generate_rpm::cli::Compression }]], 
      raw_vals: [["zstd"]], 
      ignore_case: false }] }, 
    subcommand: None } }) }

[cat-in-136]

To my surprise, it turned out that the contents of matches were different between debug and release target: presence of valid_args and valid_subcommands. This is the reason why the release build does not reproduce the issue.
Anyway, as you indicates, I agree with matches.subcommand_matches("generate-rpm") would be preferred (regardless release target).

[cat-in-136]

I confirmed that its behavior itself works fine.

build	Cargo.toml release	--set-metadata	subcommand?	Result with fix candidate	Note
debug				PASS	Release=1
debug			generate-rpm	PASS	Release=1
debug		1.el9		PASS	Release=1.el9
debug		1.el9	generate-rpm	PASS	Release=1.el9
debug	1.el8			PASS	Release=1.el8
debug	1.el8		generate-rpm	PASS	Release=1.el8
debug	1.el8	1.el9		PASS	Release=1.el9
debug	1.el8	1.el9	generate-rpm	PASS	Release=1.el9
release				PASS	Release=1
release			generate-rpm	PASS	Release=1
release		1.el9		PASS	Release=1.el9
release		1.el9	generate-rpm	PASS	Release=1.el9
release	1.el8			PASS	Release=1.el8
release	1.el8		generate-rpm	PASS	Release=1.el8
release	1.el8	1.el9		PASS	Release=1.el9
release	1.el8	1.el9	generate-rpm	PASS	Release=1.el9

FYI: Behavior before the fix (v0.15.1)

build	Cargo.toml release	--set-metadata	subcommand?	Actual result	Note
debug				PASS	Release=1
debug			generate-rpm	FAIL(panicked)	"metadata_overwrite" is not an id of an argument or a group.
debug		1.el9		PASS	Release=1.el9
debug		1.el9	generate-rpm	FAIL(panicked)	"metadata_overwrite" is not an id of an argument or a group.
debug	1.el8			PASS	Release=1.el8
debug	1.el8		generate-rpm	FAIL(panicked)	"metadata_overwrite" is not an id of an argument or a group.
debug	1.el8	1.el9		PASS	Release=1.el9
debug	1.el8	1.el9	generate-rpm	FAIL(panicked)	"metadata_overwrite" is not an id of an argument or a group.
release				PASS	Release=1
release			generate-rpm	PASS	Release=1
release		1.el9		PASS	Release=1.el9
release		1.el9	generate-rpm	FAIL	Release=1
release	1.el8			PASS	Release=1.el8
release	1.el8		generate-rpm	PASS	Release=1.el8
release	1.el8	1.el9		PASS	Release=1.el9
release	1.el8	1.el9	generate-rpm	FAIL	Release=1.el8

[dsteeley]

@cat-in-136 Thank you for the thorough testing that you've done here. Are there any changes you'd like me to make before getting the fix merged and released?

[cat-in-136]

Please check my review. (I've added @ mention to the review)

[dsteeley]

Please check my review. (I've added @ mention to the review)

Am I looking in the wrong place? I'm not able to see any review comment on this PR.