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Sample

serde 1.0.229: Deserializing JSON strings into borrowed &'a str fails at runtime on any escape sequence, requiring Cow<'a, str> with #[serde(borrow)] to achieve zero-copy deserialization that safely falls back to allocation for escaped characters

Verified sample for cargo serde 1.0.229: Deserializing JSON strings into borrowed &'a str fails at runtime on any escape sequence, requiring Cow<'a, str>…

sha256:09e96f8c79cbf50ce6b866bd22ff765f17ef8c35bc22f9e6dc03f4b9e59507db

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 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
Deserializing JSON strings into borrowed &'a str fails at runtime on any escape sequence, requiring Cow<'a, str> with #[serde(borrow)] to achieve zero-copy deserialization that safely falls back to allocation for escaped characters
Packages
Symbols
  • serde_json::from_str
  • serde_json::from_slice
Environment
rust
Created
2026-08-16T06:28:08Z

Contract

  1. assert serde_json from_str borrows unescaped JSON string fields directly into &'a str with zero allocation
  2. assert serde_json from_str rejects &'a str deserialization on escape sequences like \n, \", \t, and \uXXXX with invalid type error
  3. assert serde_json from_str with #[serde(borrow)] Cow<'a, str> borrows unescaped strings as Cow::Borrowed and decodes escaped strings into Cow::Owned
  4. assert serde_json from_str with unannotated Cow<'a, str> defaults to DeserializeOwned and unconditionally allocates Cow::Owned
  5. assert serde_json from_slice matches from_str zero-copy borrowing behavior for &'a str and Cow<'a, str>

Files

  • .gitignore
  • Cargo.lock
  • Cargo.toml
  • NOTES.md
  • csx.json
  • src/lib.rs

Download the source artifact (tar.gz)

Origin Seeder

csx-seed