crates.io · crates:once_cell
once_cell active
Single assignment cells and lazy values.
| Latest stable version | 1.21.4 |
|---|---|
| Published | 2026-03-12 10:59:52 UTC |
| Install | cargo add once_cell |
| Minimum Rust version (rust-version) | Rust ≥ 1.65 |
| License | MIT OR Apache-2.0 |
| Advisories on latest version | none known |
| Last verified | 2026-10-08 19:49:12 UTC |
| Sources | api.osv.dev, crates.io |
Maintenance
| Activity | slowing down |
|---|---|
| Last stable release | 2026-03-12 10:59:52 UTC · 210 days ago |
| Stable releases in the last 12 months | 1 |
| Published versions | 67 |
Heuristic based only on release dates; it does not measure issue or security response times.
Version history
| Version | Published |
|---|---|
1.21.4 | 2026-03-12 10:59:52 UTC |
1.21.3 | 2025-03-28 17:15:56 UTC |
1.21.2 | 2025-03-27 16:57:46 UTC |
1.21.1 | 2025-03-13 18:21:53 UTC |
1.21.0 | 2025-03-10 16:35:01 UTC |
1.20.3 | 2025-02-06 21:26:37 UTC |
1.20.2 | 2024-10-05 16:17:40 UTC |
1.20.1 | 2024-09-29 14:14:30 UTC |
1.20.0 withdrawn | 2024-09-13 21:45:38 UTC |
1.19.0 | 2023-12-07 11:11:59 UTC |
1.18.0 | 2023-06-04 12:24:36 UTC |
1.17.2 | 2023-05-29 10:10:45 UTC |
1.17.1 | 2023-02-14 15:31:58 UTC |
1.17.0 | 2022-12-29 17:34:46 UTC |
1.16.0 | 2022-10-29 09:07:19 UTC |
1.15.0 | 2022-09-20 20:20:31 UTC |
1.14.0 | 2022-09-02 12:01:44 UTC |
1.13.1 | 2022-08-16 13:13:11 UTC |
1.13.0 | 2022-07-04 23:57:12 UTC |
1.12.1 | 2022-07-04 10:44:06 UTC |
Showing the 20 most recent of 61 versions. JSON
Version compatibility
Newest stable version that declares support for each runtime version (from the requirements published with each version).
| Runtime | Newest compatible version |
|---|---|
rust 1.63 | 1.20.3 |
rust 1.70 | 1.21.4 |
rust 1.75 | 1.21.4 |
rust 1.80 | 1.21.4 |
rust 1.85 | 1.21.4 |
rust 1.90 | 1.21.4 |
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Frequently asked questions
What is the latest version of once_cell?
The latest stable version of once_cell is 1.21.4, published on 2026-03-12. Verified by Vigia on 2026-10-08.
How do I install the latest version of once_cell?
Run cargo add once_cell. The latest stable version is 1.21.4 (verified 2026-10-08).
Is once_cell deprecated?
No. once_cell is not marked as deprecated in the registry.
Which Rust version does once_cell require?
once_cell 1.21.4 declares this requirement: Rust ≥ 1.65.
Does once_cell 1.21.4 have known vulnerabilities?
No known advisories affect once_cell 1.21.4 according to the data Vigia checks.
Is once_cell still maintained?
once_cell published 1 stable releases in the last 12 months; the most recent was 210 days ago. Activity: slowing down.
Observed changes
No changes observed yet since Vigia started tracking this package.
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