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
If none match selects 304 only for safe retrieval · case 01
If none match selects 304 only for safe retrieval.
If none match selects 304 only for safe retrieval · case 02
If none match selects 304 only for safe retrieval.
If none match selects 304 only for safe retrieval · case 03
If none match selects 304 only for safe retrieval.
If none match selects 304 only for safe retrieval · case 04
If none match selects 304 only for safe retrieval.
If none match selects 304 only for safe retrieval · case 05
If none match selects 304 only for safe retrieval.
If none match takes precedence over modified since · case 01
If none match takes precedence over modified since.
If none match takes precedence over modified since · case 02
If none match takes precedence over modified since.
If none match takes precedence over modified since · case 03
If none match takes precedence over modified since.
If none match takes precedence over modified since · case 04
If none match takes precedence over modified since.
If none match takes precedence over modified since · case 05
If none match takes precedence over modified since.
If unmodified since is ignored when if match present · case 01
If unmodified since is ignored when if match present.
If unmodified since is ignored when if match present · case 02
If unmodified since is ignored when if match present.
If unmodified since is ignored when if match present · case 03
If unmodified since is ignored when if match present.
If unmodified since is ignored when if match present · case 04
If unmodified since is ignored when if match present.
If unmodified since is ignored when if match present · case 05
If unmodified since is ignored when if match present.
Cached head updates do not replace get payload · case 01
Cached head updates do not replace get payload.
Cached head updates do not replace get payload · case 02
Cached head updates do not replace get payload.
Cached head updates do not replace get payload · case 03
Cached head updates do not replace get payload.
Cached head updates do not replace get payload · case 04
Cached head updates do not replace get payload.
Cached head updates do not replace get payload · case 05
Cached head updates do not replace get payload.
Cache variants distinguish missing header from empty header · case 01
Cache variants distinguish missing header from empty header.
Cache variants distinguish missing header from empty header · case 02
Cache variants distinguish missing header from empty header.
Cache variants distinguish missing header from empty header · case 03
Cache variants distinguish missing header from empty header.
Cache variants distinguish missing header from empty header · case 04
Cache variants distinguish missing header from empty header.
Cache variants distinguish missing header from empty header · case 05
Cache variants distinguish missing header from empty header.
Cache warning removal preserves persistent warnings · case 01
Cache warning removal preserves persistent warnings.
Cache warning removal preserves persistent warnings · case 02
Cache warning removal preserves persistent warnings.
Cache warning removal preserves persistent warnings · case 03
Cache warning removal preserves persistent warnings.
Cache warning removal preserves persistent warnings · case 04
Cache warning removal preserves persistent warnings.
Cache warning removal preserves persistent warnings · case 05
Cache warning removal preserves persistent warnings.
Media specificity outranks wildcard before quality · case 01
Media specificity outranks wildcard before quality.
Media specificity outranks wildcard before quality · case 02
Media specificity outranks wildcard before quality.
Media specificity outranks wildcard before quality · case 03
Media specificity outranks wildcard before quality.
Media specificity outranks wildcard before quality · case 04
Media specificity outranks wildcard before quality.
Media specificity outranks wildcard before quality · case 05
Media specificity outranks wildcard before quality.
Zero quality excludes media candidates · case 01
Zero quality excludes media candidates.
Zero quality excludes media candidates · case 02
Zero quality excludes media candidates.
Zero quality excludes media candidates · case 03
Zero quality excludes media candidates.
Zero quality excludes media candidates · case 04
Zero quality excludes media candidates.
Zero quality excludes media candidates · case 05
Zero quality excludes media candidates.
Equal quality retains server preference order · case 01
Equal quality retains server preference order.
Equal quality retains server preference order · case 02
Equal quality retains server preference order.
Equal quality retains server preference order · case 03
Equal quality retains server preference order.
Equal quality retains server preference order · case 04
Equal quality retains server preference order.
Equal quality retains server preference order · case 05
Equal quality retains server preference order.
Media subtype wildcard does not cross top level types · case 01
Media subtype wildcard does not cross top level types.
Media subtype wildcard does not cross top level types · case 02
Media subtype wildcard does not cross top level types.
Media subtype wildcard does not cross top level types · case 03
Media subtype wildcard does not cross top level types.
Media subtype wildcard does not cross top level types · case 04
Media subtype wildcard does not cross top level types.
Media subtype wildcard does not cross top level types · case 05
Media subtype wildcard does not cross top level types.
Media parameters must all match selected representation · case 01
Media parameters must all match selected representation.
Media parameters must all match selected representation · case 02
Media parameters must all match selected representation.
Media parameters must all match selected representation · case 03
Media parameters must all match selected representation.
Media parameters must all match selected representation · case 04
Media parameters must all match selected representation.
Media parameters must all match selected representation · case 05
Media parameters must all match selected representation.
Accept encoding explicit entry overrides star · case 01
Accept encoding explicit entry overrides star.
Accept encoding explicit entry overrides star · case 02
Accept encoding explicit entry overrides star.
Accept encoding explicit entry overrides star · case 03
Accept encoding explicit entry overrides star.
Accept encoding explicit entry overrides star · case 04
Accept encoding explicit entry overrides star.
Accept encoding explicit entry overrides star · case 05
Accept encoding explicit entry overrides star.
Identity encoding is implicit unless specifically excluded · case 01
Identity encoding is implicit unless specifically excluded.
Identity encoding is implicit unless specifically excluded · case 02
Identity encoding is implicit unless specifically excluded.
Identity encoding is implicit unless specifically excluded · case 03
Identity encoding is implicit unless specifically excluded.
Identity encoding is implicit unless specifically excluded · case 04
Identity encoding is implicit unless specifically excluded.
Identity encoding is implicit unless specifically excluded · case 05
Identity encoding is implicit unless specifically excluded.
Empty accept encoding requires identity · case 01
Empty accept encoding requires identity.
Empty accept encoding requires identity · case 02
Empty accept encoding requires identity.
Empty accept encoding requires identity · case 03
Empty accept encoding requires identity.
Empty accept encoding requires identity · case 04
Empty accept encoding requires identity.
Empty accept encoding requires identity · case 05
Empty accept encoding requires identity.
Compression skips already coded representations · case 01
Compression skips already coded representations.
Compression skips already coded representations · case 02
Compression skips already coded representations.
Compression skips already coded representations · case 03
Compression skips already coded representations.
Compression skips already coded representations · case 04
Compression skips already coded representations.
Compression skips already coded representations · case 05
Compression skips already coded representations.
Compression benefit includes content coding overhead · case 01
Compression benefit includes content coding overhead.
Compression benefit includes content coding overhead · case 02
Compression benefit includes content coding overhead.
Compression benefit includes content coding overhead · case 03
Compression benefit includes content coding overhead.
Compression benefit includes content coding overhead · case 04
Compression benefit includes content coding overhead.
Compression benefit includes content coding overhead · case 05
Compression benefit includes content coding overhead.
Content length after coding describes transmitted octets · case 01
Content length after coding describes transmitted octets.
Content length after coding describes transmitted octets · case 02
Content length after coding describes transmitted octets.
Content length after coding describes transmitted octets · case 03
Content length after coding describes transmitted octets.
Content length after coding describes transmitted octets · case 04
Content length after coding describes transmitted octets.
Content length after coding describes transmitted octets · case 05
Content length after coding describes transmitted octets.
Language basic filtering requires subtag boundary · case 01
Language basic filtering requires subtag boundary.
Language basic filtering requires subtag boundary · case 02
Language basic filtering requires subtag boundary.
Language basic filtering requires subtag boundary · case 03
Language basic filtering requires subtag boundary.
Language basic filtering requires subtag boundary · case 04
Language basic filtering requires subtag boundary.
Language basic filtering requires subtag boundary · case 05
Language basic filtering requires subtag boundary.
Language lookup truncates rightmost subtags · case 01
Language lookup truncates rightmost subtags.
Language lookup truncates rightmost subtags · case 02
Language lookup truncates rightmost subtags.
Language lookup truncates rightmost subtags · case 03
Language lookup truncates rightmost subtags.
Language lookup truncates rightmost subtags · case 04
Language lookup truncates rightmost subtags.
Language lookup truncates rightmost subtags · case 05
Language lookup truncates rightmost subtags.
Language selection does not sort quality lexicographically · case 01
Language selection does not sort quality lexicographically.
Language selection does not sort quality lexicographically · case 02
Language selection does not sort quality lexicographically.
Language selection does not sort quality lexicographically · case 03
Language selection does not sort quality lexicographically.
Language selection does not sort quality lexicographically · case 04
Language selection does not sort quality lexicographically.
Language selection does not sort quality lexicographically · case 05
Language selection does not sort quality lexicographically.
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 ↗