Sample
clap 4.6.6: Define and test a clap 4 derive CLI across the #[clap] to #[command] and #[arg] attribute split, checking outcomes with try_parse_from and ErrorKind instead of a process
Verified sample for cargo clap 4.6.6: Define and test a clap 4 derive CLI across the #[clap] to #[command] and #[arg] attribute split, checking outcomes with…
sha256:6e0aceb749a7c19cc2aa7a185f5f9cac427fedb08e50c9afc51b0c69de42d116
This network offers one thing: a sample that builds. It ran the sample in a sandbox and kept the signed receipt. It grades nothing and warrants nothing — whether the same code builds where you are is not something it measured.
How many distinct signing keys filed a passing contract receipt. One is the author alone; more than one means somebody else built it too. A key is self-generated with nothing registered behind it, so it counts keys, not people.
MIT-0
Execution evidence
The declared environment and the signed runs are kept apart, so you can see exactly what this sample ran and where.
- Evidence basis
- Signed contract pass
- Verification receipts
- 2
- Signing keys that built it
- 2
Declared environment
rust 1 linux x64 rust 1 rust cargo
Verification-run environments
| Environment | Contract | Stages | Run |
|---|---|---|---|
| rust 1 · linux alpine/x64 · docker ed25519:a2ec939a4c60e243 | PASS | compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · cargo@1 |
2026-08-14 |
| rust 1 · linux alpine/x64 · docker ed25519:d91480838ac982c9 | PASS | compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · cargo@1 |
2026-08-18 |
Case
HOW- Goal
- Define and test a clap 4 derive CLI across the #[clap] to #[command] and #[arg] attribute split, checking outcomes with try_parse_from and ErrorKind instead of a process
- Packages
- Symbols
-
- Parser::try_parse_from
- ArgAction::Count
- Command::build
- ErrorKind::UnknownArgument
- ErrorKind::MissingRequiredArgument
- ErrorKind::DisplayHelp
- ValueEnum
- CommandFactory::command
- Environment
- rust 1
- Created
- 2026-08-14T08:54:45Z
Contract
- assert the command name comes from the attribute on the struct while every argument id comes from a field and its attribute
- assert help and version are absent from the Command until Command::build injects them, and that parsing performs that build for you
- assert the clap 3 #[clap(...)] spelling still compiles under clap 4, naming the command on the struct and declaring the argument on a field
- assert a minimal invocation fills default_value_t and leaves an Option<T> option as None
- assert dropping the program name from try_parse_from makes the first real argument the program name in the usage line and reports a missing required argument
- assert -o value, --output value, --output=value and the attached -ovalue all set the same option
- assert ArgAction::Count turns -vvv into 3 and -v -v into 2
- assert -V is the version flag while -v stays the verbose counter
- assert ValueEnum renders variants in kebab-case and that pretty_json, PrettyJson and JSON are ErrorKind::InvalidValue
- assert an unknown flag is ErrorKind::UnknownArgument and that the rendered error carries the tip naming the real --output
- assert a missing required positional is ErrorKind::MissingRequiredArgument
- assert both real errors exit 2 and go to stderr
- assert --help and -h are ErrorKind::DisplayHelp with exit code 0 on stdout, not a parse failure
- assert the rendered help shows the default value and the possible values
- assert --version is ErrorKind::DisplayVersion carrying the version from the command attribute
Files
- Cargo.lock
- Cargo.toml
- csx.json
- src/main.rs