Sample
clap 4.6.6: Handle Vec<T> single-value positional hijacking, comma delimiting, Option<Option<T>> optional values, and trailing vararg hyphen capture across clap 4 derive
Verified sample for cargo clap 4.6.6: Handle Vec<T> single-value positional hijacking, comma delimiting, Option<Option<T>> optional values, and trailing…
sha256:cfd06501ca8230963d4fafb67ed5c470654c03f69cbdd8cf64c3fcf4ba7bc0c7
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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 linux x64 rust rust cargo
Verification-run environments
| Environment | Contract | Stages | Run |
|---|---|---|---|
| rust 1 · linux alpine/x64 · docker ed25519:d91480838ac982c9 | PASS | compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · cargo@1 |
2026-08-16 |
| rust 1 · linux alpine/x64 · docker ed25519:2175b912ea1c23b1 | PASS | compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · cargo@1 |
2026-08-18 |
Case
HOW- Goal
- Handle Vec<T> single-value positional hijacking, comma delimiting, Option<Option<T>> optional values, and trailing vararg hyphen capture across clap 4 derive
- Packages
- Symbols
-
- Parser::try_parse_from
- ArgAction::Append
- ArgAction::Set
- ErrorKind::ArgumentConflict
- ErrorKind::UnknownArgument
- Environment
- rust
- Created
- 2026-08-16T08:06:03Z
Contract
- assert Vec<T> options default to num_args = 1, causing --file a b to populate files with ['a'] and silently route 'b' to the positional target
- assert num_args = 1.. explicitly enables greedy space-separated multi-value consumption into a Vec<T> field
- assert comma-separated inputs require value_delimiter = ',' to split into distinct Vec elements rather than a single string
- assert duplicate scalar flags with default ArgAction::Set fail with ErrorKind::ArgumentConflict rather than silently overwriting
- assert Option<Option<T>> distinguishes omitted flags (None), bare flags without values (Some(None)), and flags with values (Some(Some(T)))
- assert trailing_var_arg = true with allow_hyphen_values = true captures subsequent flags into positional passthrough without double-hyphen delimiters
- assert last = true strictly requires the double-hyphen delimiter to capture hyphenated arguments into trailing positionals
Files
- Cargo.lock
- Cargo.toml
- NOTES.md
- csx.json
- src/lib.rs
- tests/contract.rs