Understand the failure.
Verify the repair.
Small, reproducible software failures. The broken implementation, the fix that didn’t work, and the one that passed—preserved together.
Explore the cases ↓How results are verified ↗WHAT THE ARCHIVE CONTAINS
100840 executable cases. 20168 are open.
Every case records the implementation that fails, the fix that did not work, and the repair that passed its checks—with recorded outputs and source hashes. This release adds 100840 cases across 20168 failure mechanisms and 254 domains.
The open tier gives you the failure and the unsuccessful fix for one case in every mechanism. The remaining 80672 cases, 5 variants per mechanism, are member-only: the verified repair, its recorded checks, and the full fixture suite are held in the member archive. Read the methodology ↗
A RECORD OF WHAT WENT WRONG
Browse the archive / 100840
Retry classification includes replacement and deletion methods · case 01
Retry classification includes replacement and deletion methods.
Retry classification includes replacement and deletion methods · case 02
Retry classification includes replacement and deletion methods.
Retry classification includes replacement and deletion methods · case 03
Retry classification includes replacement and deletion methods.
Retry classification includes replacement and deletion methods · case 04
Retry classification includes replacement and deletion methods.
Retry classification includes replacement and deletion methods · case 05
Retry classification includes replacement and deletion methods.
An Allow response includes HEAD when GET is available · case 01
An Allow response includes HEAD when GET is available.
An Allow response includes HEAD when GET is available · case 02
An Allow response includes HEAD when GET is available.
An Allow response includes HEAD when GET is available · case 03
An Allow response includes HEAD when GET is available.
An Allow response includes HEAD when GET is available · case 04
An Allow response includes HEAD when GET is available.
An Allow response includes HEAD when GET is available · case 05
An Allow response includes HEAD when GET is available.
Method token matching preserves case sensitivity · case 01
Method token matching preserves case sensitivity.
Method token matching preserves case sensitivity · case 02
Method token matching preserves case sensitivity.
Method token matching preserves case sensitivity · case 03
Method token matching preserves case sensitivity.
Method token matching preserves case sensitivity · case 04
Method token matching preserves case sensitivity.
Method token matching preserves case sensitivity · case 05
Method token matching preserves case sensitivity.
Continue is emitted only before an expected request body · case 01
Continue is emitted only before an expected request body.
Continue is emitted only before an expected request body · case 02
Continue is emitted only before an expected request body.
Continue is emitted only before an expected request body · case 03
Continue is emitted only before an expected request body.
Continue is emitted only before an expected request body · case 04
Continue is emitted only before an expected request body.
Continue is emitted only before an expected request body · case 05
Continue is emitted only before an expected request body.
Unsupported expectations are rejected independently of body length · case 01
Unsupported expectations are rejected independently of body length.
Unsupported expectations are rejected independently of body length · case 02
Unsupported expectations are rejected independently of body length.
Unsupported expectations are rejected independently of body length · case 03
Unsupported expectations are rejected independently of body length.
Unsupported expectations are rejected independently of body length · case 04
Unsupported expectations are rejected independently of body length.
Unsupported expectations are rejected independently of body length · case 05
Unsupported expectations are rejected independently of body length.
CONNECT uses authority form and server-wide OPTIONS uses asterisk form · case 01
CONNECT uses authority form and server-wide OPTIONS uses asterisk form.
CONNECT uses authority form and server-wide OPTIONS uses asterisk form · case 02
CONNECT uses authority form and server-wide OPTIONS uses asterisk form.
CONNECT uses authority form and server-wide OPTIONS uses asterisk form · case 03
CONNECT uses authority form and server-wide OPTIONS uses asterisk form.
CONNECT uses authority form and server-wide OPTIONS uses asterisk form · case 04
CONNECT uses authority form and server-wide OPTIONS uses asterisk form.
CONNECT uses authority form and server-wide OPTIONS uses asterisk form · case 05
CONNECT uses authority form and server-wide OPTIONS uses asterisk form.
Redirect rewriting preserves methods for 307 and 308 · case 01
Redirect rewriting preserves methods for 307 and 308.
Redirect rewriting preserves methods for 307 and 308 · case 02
Redirect rewriting preserves methods for 307 and 308.
Redirect rewriting preserves methods for 307 and 308 · case 03
Redirect rewriting preserves methods for 307 and 308.
Redirect rewriting preserves methods for 307 and 308 · case 04
Redirect rewriting preserves methods for 307 and 308.
Redirect rewriting preserves methods for 307 and 308 · case 05
Redirect rewriting preserves methods for 307 and 308.
A relative Location resolves against the current request URL · case 01
A relative Location resolves against the current request URL.
A relative Location resolves against the current request URL · case 02
A relative Location resolves against the current request URL.
A relative Location resolves against the current request URL · case 03
A relative Location resolves against the current request URL.
A relative Location resolves against the current request URL · case 04
A relative Location resolves against the current request URL.
A relative Location resolves against the current request URL · case 05
A relative Location resolves against the current request URL.
A redirect without a fragment inherits the original fragment · case 01
A redirect without a fragment inherits the original fragment.
A redirect without a fragment inherits the original fragment · case 02
A redirect without a fragment inherits the original fragment.
A redirect without a fragment inherits the original fragment · case 03
A redirect without a fragment inherits the original fragment.
A redirect without a fragment inherits the original fragment · case 04
A redirect without a fragment inherits the original fragment.
A redirect without a fragment inherits the original fragment · case 05
A redirect without a fragment inherits the original fragment.
Loop detection ignores URL fragments but retains query identity · case 01
Loop detection ignores URL fragments but retains query identity.
Loop detection ignores URL fragments but retains query identity · case 02
Loop detection ignores URL fragments but retains query identity.
Loop detection ignores URL fragments but retains query identity · case 03
Loop detection ignores URL fragments but retains query identity.
Loop detection ignores URL fragments but retains query identity · case 04
Loop detection ignores URL fragments but retains query identity.
Loop detection ignores URL fragments but retains query identity · case 05
Loop detection ignores URL fragments but retains query identity.
A redirect budget charges redirects rather than the initial request · case 01
A redirect budget charges redirects rather than the initial request.
A redirect budget charges redirects rather than the initial request · case 02
A redirect budget charges redirects rather than the initial request.
A redirect budget charges redirects rather than the initial request · case 03
A redirect budget charges redirects rather than the initial request.
A redirect budget charges redirects rather than the initial request · case 04
A redirect budget charges redirects rather than the initial request.
A redirect budget charges redirects rather than the initial request · case 05
A redirect budget charges redirects rather than the initial request.
Negative Retry-After delays are clamped before imposing a cap · case 01
Negative Retry-After delays are clamped before imposing a cap.
Negative Retry-After delays are clamped before imposing a cap · case 02
Negative Retry-After delays are clamped before imposing a cap.
Negative Retry-After delays are clamped before imposing a cap · case 03
Negative Retry-After delays are clamped before imposing a cap.
Negative Retry-After delays are clamped before imposing a cap · case 04
Negative Retry-After delays are clamped before imposing a cap.
Negative Retry-After delays are clamped before imposing a cap · case 05
Negative Retry-After delays are clamped before imposing a cap.
Status retries require both a configured status and a replayable body · case 01
Status retries require both a configured status and a replayable body.
Status retries require both a configured status and a replayable body · case 02
Status retries require both a configured status and a replayable body.
Status retries require both a configured status and a replayable body · case 03
Status retries require both a configured status and a replayable body.
Status retries require both a configured status and a replayable body · case 04
Status retries require both a configured status and a replayable body.
Status retries require both a configured status and a replayable body · case 05
Status retries require both a configured status and a replayable body.
An unsafe request cannot replay after any bytes may have reached the peer · case 01
An unsafe request cannot replay after any bytes may have reached the peer.
An unsafe request cannot replay after any bytes may have reached the peer · case 02
An unsafe request cannot replay after any bytes may have reached the peer.
An unsafe request cannot replay after any bytes may have reached the peer · case 03
An unsafe request cannot replay after any bytes may have reached the peer.
An unsafe request cannot replay after any bytes may have reached the peer · case 04
An unsafe request cannot replay after any bytes may have reached the peer.
An unsafe request cannot replay after any bytes may have reached the peer · case 05
An unsafe request cannot replay after any bytes may have reached the peer.
A retry starts only when both backoff and minimum service time fit · case 01
A retry starts only when both backoff and minimum service time fit.
A retry starts only when both backoff and minimum service time fit · case 02
A retry starts only when both backoff and minimum service time fit.
A retry starts only when both backoff and minimum service time fit · case 03
A retry starts only when both backoff and minimum service time fit.
A retry starts only when both backoff and minimum service time fit · case 04
A retry starts only when both backoff and minimum service time fit.
A retry starts only when both backoff and minimum service time fit · case 05
A retry starts only when both backoff and minimum service time fit.
Deterministic full jitter spans the entire capped delay interval · case 01
Deterministic full jitter spans the entire capped delay interval.
Deterministic full jitter spans the entire capped delay interval · case 02
Deterministic full jitter spans the entire capped delay interval.
Deterministic full jitter spans the entire capped delay interval · case 03
Deterministic full jitter spans the entire capped delay interval.
Deterministic full jitter spans the entire capped delay interval · case 04
Deterministic full jitter spans the entire capped delay interval.
Deterministic full jitter spans the entire capped delay interval · case 05
Deterministic full jitter spans the entire capped delay interval.
An inclusive byte endpoint yields one more byte than endpoint subtraction · case 01
An inclusive byte endpoint yields one more byte than endpoint subtraction.
An inclusive byte endpoint yields one more byte than endpoint subtraction · case 02
An inclusive byte endpoint yields one more byte than endpoint subtraction.
An inclusive byte endpoint yields one more byte than endpoint subtraction · case 03
An inclusive byte endpoint yields one more byte than endpoint subtraction.
An inclusive byte endpoint yields one more byte than endpoint subtraction · case 04
An inclusive byte endpoint yields one more byte than endpoint subtraction.
An inclusive byte endpoint yields one more byte than endpoint subtraction · case 05
An inclusive byte endpoint yields one more byte than endpoint subtraction.
An open byte range clips at representation length and rejects starts beyond it · case 01
An open byte range clips at representation length and rejects starts beyond it.
An open byte range clips at representation length and rejects starts beyond it · case 02
An open byte range clips at representation length and rejects starts beyond it.
An open byte range clips at representation length and rejects starts beyond it · case 03
An open byte range clips at representation length and rejects starts beyond it.
An open byte range clips at representation length and rejects starts beyond it · case 04
An open byte range clips at representation length and rejects starts beyond it.
An open byte range clips at representation length and rejects starts beyond it · case 05
An open byte range clips at representation length and rejects starts beyond it.
A suffix range is bounded by representation length and excludes zero suffixes · case 01
A suffix range is bounded by representation length and excludes zero suffixes.
A suffix range is bounded by representation length and excludes zero suffixes · case 02
A suffix range is bounded by representation length and excludes zero suffixes.
A suffix range is bounded by representation length and excludes zero suffixes · case 03
A suffix range is bounded by representation length and excludes zero suffixes.
A suffix range is bounded by representation length and excludes zero suffixes · case 04
A suffix range is bounded by representation length and excludes zero suffixes.
A suffix range is bounded by representation length and excludes zero suffixes · case 05
A suffix range is bounded by representation length and excludes zero suffixes.
A range set is unsatisfiable only when every requested start is beyond the representation · case 01
A range set is unsatisfiable only when every requested start is beyond the representation.
A range set is unsatisfiable only when every requested start is beyond the representation · case 02
A range set is unsatisfiable only when every requested start is beyond the representation.
A range set is unsatisfiable only when every requested start is beyond the representation · case 03
A range set is unsatisfiable only when every requested start is beyond the representation.
A range set is unsatisfiable only when every requested start is beyond the representation · case 04
A range set is unsatisfiable only when every requested start is beyond the representation.
A range set is unsatisfiable only when every requested start is beyond the representation · case 05
A range set is unsatisfiable only when every requested start is beyond the representation.
INSPECTABLE BY DESIGN
Every result has a runnable source.
Runnable implementations with recorded outputs, source hashes, and explicit contracts. Related variants share a failure mechanism and belong together in evaluation splits.
Read the methodology ↗