Crates / fragile
Rust crate · real downloads · data Oct 24, 2026
fragile downloads, and should you depend on it?
Provides wrapper types for sending non-send values to other threads. crates.io · docs.rs · repository
Owned on crates.io by mitsuhiko · is it still maintained?
Feature flags + Cargo.toml picker
Few direct dependents and losing ground.
fragile: only 24 crates name it directly; most of its downloads come in through mockall; downloads don't spike on releases.
How this verdict is decided (4 rules)
- Usage: crates.io reverse dependencies (crates that list it as a dependency): 10,000+ = foundational, 1,000+ = widely used, 100+ = established, under 100 = few direct dependents.
- Direction: the median quiet day in the last 30 days of the window against the first 30, read against the median tracked crate (the whole field moved +39% from late summer to October, so a raw trend says nothing). 10%+ ahead of the field = gaining; 10%+ behind = losing ground; otherwise steady. Steady with no release in 2+ years = quiet for years.
- Release spikes: the median release-window day against the quiet-day baseline: under 1.15x = no spike, 1.15x to 1.3x = small bumps, 1.3x or more = jumps on release days.
- Release recency: days since the newest version that was not yanked, from crates.io publish times.
release window (release day + next day)quiet dayquiet-day median · download the 89 days as CSV
The numbers in one paragraphfragile got 27,327,746 crates.io downloads from Jul 27, 2026 to Oct 23, 2026. 2% of them landed within 2 days of one of its 1 release. On the other 87 quiet days it got a median of 351,238 a day, about 2,458,666 a week. Capping release days at that baseline leaves 27,327,746 release-adjusted downloads for the window.
What this means if you're choosing a dependency
- You rarely add this one yourself. Only 24 crates name it directly; its downloads arrive through mockall.
- Actively released. 3.0.0 shipped 50 days ago (Sep 4, 2026).
- Fit check: license Apache-2.0, edition 2018, needs Rust 1.56.0 or newer (from the latest version's manifest).
- Compare it by the baseline, not the raw count. 2% of its 27,327,746 downloads in the window landed within 2 days of a release; the steady number is 351,238 a day.
Alternatives that do a similar job
Crates that share its crates.io category or keywords, most similar first. Each line is the crate's own description, then how it compares on the same data.
Its place in the dependency graph
Built on fragile
1 of the 1000 crates we track depend on it directly (biggest first).
fragile builds on
Tracked crates its latest version (3.0.0) depends on (optional ones marked).
What the chart says
- Weekend quiet days ran at 39% of weekday quiet days (142,761 vs 366,586). A dip that deep is the signature of work-week CI pipelines and developers building on weekdays.
- Biggest day: 537,706 on Oct 22, 2026, a quiet day with no release nearby.
Every number
| All-time downloads | 161,173,628 (rank #687 on crates.io by all-time downloads) |
| Downloads in the window | 27,327,746 (Jul 27, 2026 to Oct 23, 2026, 89 days) |
| Within 2 days of a release | 472,259 (1.7%) |
| Quiet-day median (baseline) | 351,238 a day; weekdays 366,586, weekends 142,761 |
| Release-adjusted downloads | 27,327,746 (release-window days capped at the baseline) |
| Baseline rank | #805 of the 1000 crates we track |
| Quiet-day trend | +10% raw, -21% against the median tracked crate (+39%) |
| Releases in the window | 1 |
| Versions published, ever | 13 |
| Latest version | 3.0.0, published Sep 4, 2026 (license Apache-2.0, edition 2018, MSRV 1.56.0) |
| First published | Jun 20, 2018 |
| Reverse dependencies | 24 |
Releases in the window
Each one opens a 2-day release window on the chart.
| Version | Published | Downloads that version got (lifetime) |
|---|---|---|
| 3.0.0 | Sep 4, 2026 | 33,335 |
How we compute this
crates.io counts every download, including CI runners, mirrors and bots that fetch each new version, so raw counts run high (why, in The Manual). We split the last 89 days into release windows (the day a version of fragile was published, plus the next day) and quiet days, and use the median quiet day as the baseline: an upper bound on steady use, never a head count. The method and data come from our study of 90 days of crates.io data from 69 crates, featured in This Week in Rust #674; check any crate live with the real-downloads checker.
Badge for your README
Maintainers can show the baseline in a README. It is optional, updates when we refresh the data, and links back here. Preview, then copy:
README, light
README, dark
Publishing a crate of your own? How to publish a Rust crate to crates.io, step by step.
Categories
Sources
- Daily downloads: crates.io API, /crates/fragile/downloads (last 90 days, all versions), fetched Oct 24, 2026.
- Versions and publish times: crates.io API, /crates/fragile/versions, same fetch.
- Reverse dependencies: crates.io reverse dependencies, same fetch. Dependency edges between tracked crates: each crate's default version, crates.io API.
- Fetched politely (one request every 2 seconds, identified User-Agent) per the crates.io data access policy. Data is crates.io's; the release-window split, baseline and verdict rules are ours, CC BY 4.0.
Up next
Next by real downloads: The next crate down the real-downloads ranking: 349,411 a day. Few direct dependents and losing ground.utf16_iterRust crate. Iterator by char over potentially-invalid UTF-16 in &[u16]. Real use: 349K downloads a day on quiet days; 3 crates depend on it.Read it next →Also worth your time