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
Strip blocked attachments under a content policy: extension normalization · case 01
SETUP.EXE passes because the extension comparison is case-sensitive.
Strip blocked attachments under a content policy: extension normalization · case 02
SETUP.EXE passes because the extension comparison is case-sensitive.
Strip blocked attachments under a content policy: extension normalization · case 03
SETUP.EXE passes because the extension comparison is case-sensitive.
Strip blocked attachments under a content policy: extension normalization · case 04
SETUP.EXE passes because the extension comparison is case-sensitive.
Strip blocked attachments under a content policy: extension normalization · case 05
SETUP.EXE passes because the extension comparison is case-sensitive.
Strip blocked attachments under a content policy: signed inheritance · case 01
An attachment nested in a mixed part inside a signed message is stripped, silently breaking the signature.
Strip blocked attachments under a content policy: signed inheritance · case 02
An attachment nested in a mixed part inside a signed message is stripped, silently breaking the signature.
Strip blocked attachments under a content policy: signed inheritance · case 03
An attachment nested in a mixed part inside a signed message is stripped, silently breaking the signature.
Strip blocked attachments under a content policy: signed inheritance · case 04
An attachment nested in a mixed part inside a signed message is stripped, silently breaking the signature.
Strip blocked attachments under a content policy: signed inheritance · case 05
An attachment nested in a mixed part inside a signed message is stripped, silently breaking the signature.
Strip blocked attachments under a content policy: body exemption · case 01
A named executable marked inline slips through the policy.
Strip blocked attachments under a content policy: body exemption · case 02
A named executable marked inline slips through the policy.
Strip blocked attachments under a content policy: body exemption · case 03
A named executable marked inline slips through the policy.
Strip blocked attachments under a content policy: body exemption · case 04
A named executable marked inline slips through the policy.
Strip blocked attachments under a content policy: body exemption · case 05
A named executable marked inline slips through the policy.
Strip blocked attachments under a content policy: size boundary · case 01
Attachments exactly at the size limit are stripped.
Strip blocked attachments under a content policy: size boundary · case 02
Attachments exactly at the size limit are stripped.
Strip blocked attachments under a content policy: size boundary · case 03
Attachments exactly at the size limit are stripped.
Strip blocked attachments under a content policy: size boundary · case 04
Attachments exactly at the size limit are stripped.
Strip blocked attachments under a content policy: size boundary · case 05
Attachments exactly at the size limit are stripped.
Strip blocked attachments under a content policy: reject propagation · case 01
A signed message that cannot be cleaned is delivered with a partial action list instead of being rejected.
Strip blocked attachments under a content policy: reject propagation · case 02
A signed message that cannot be cleaned is delivered with a partial action list instead of being rejected.
Strip blocked attachments under a content policy: reject propagation · case 03
A signed message that cannot be cleaned is delivered with a partial action list instead of being rejected.
Strip blocked attachments under a content policy: reject propagation · case 04
A signed message that cannot be cleaned is delivered with a partial action list instead of being rejected.
Strip blocked attachments under a content policy: reject propagation · case 05
A signed message that cannot be cleaned is delivered with a partial action list instead of being rejected.
Decide whether a message is interpreted as MIME: first version wins · case 01
A later MIME-Version header overrides an empty first one and turns a legacy message into MIME.
Decide whether a message is interpreted as MIME: first version wins · case 02
A later MIME-Version header overrides an empty first one and turns a legacy message into MIME.
Decide whether a message is interpreted as MIME: first version wins · case 03
A later MIME-Version header overrides an empty first one and turns a legacy message into MIME.
Decide whether a message is interpreted as MIME: first version wins · case 04
A later MIME-Version header overrides an empty first one and turns a legacy message into MIME.
Decide whether a message is interpreted as MIME: first version wins · case 05
A later MIME-Version header overrides an empty first one and turns a legacy message into MIME.
Decide whether a message is interpreted as MIME: comment removal · case 01
A MIME-Version header carrying a comment is not recognised, so the message is shown as raw text.
Decide whether a message is interpreted as MIME: comment removal · case 02
A MIME-Version header carrying a comment is not recognised, so the message is shown as raw text.
Decide whether a message is interpreted as MIME: comment removal · case 03
A MIME-Version header carrying a comment is not recognised, so the message is shown as raw text.
Decide whether a message is interpreted as MIME: comment removal · case 04
A MIME-Version header carrying a comment is not recognised, so the message is shown as raw text.
Decide whether a message is interpreted as MIME: comment removal · case 05
A MIME-Version header carrying a comment is not recognised, so the message is shown as raw text.
Decide whether a message is interpreted as MIME: inner whitespace · case 01
A version written with spaces or tabs between its tokens is rejected.
Decide whether a message is interpreted as MIME: inner whitespace · case 02
A version written with spaces or tabs between its tokens is rejected.
Decide whether a message is interpreted as MIME: inner whitespace · case 03
A version written with spaces or tabs between its tokens is rejected.
Decide whether a message is interpreted as MIME: inner whitespace · case 04
A version written with spaces or tabs between its tokens is rejected.
Decide whether a message is interpreted as MIME: inner whitespace · case 05
A version written with spaces or tabs between its tokens is rejected.
Weekly BYDAY expansion honouring the week-start day: week anchor · case 01
With a Sunday week start and INTERVAL=2, the active weeks are shifted so Sunday instances land in the skipped week.
Weekly BYDAY expansion honouring the week-start day: week anchor · case 02
With a Sunday week start and INTERVAL=2, the active weeks are shifted so Sunday instances land in the skipped week.
Weekly BYDAY expansion honouring the week-start day: week anchor · case 03
With a Sunday week start and INTERVAL=2, the active weeks are shifted so Sunday instances land in the skipped week.
Weekly BYDAY expansion honouring the week-start day: week anchor · case 04
With a Sunday week start and INTERVAL=2, the active weeks are shifted so Sunday instances land in the skipped week.
Weekly BYDAY expansion honouring the week-start day: week anchor · case 05
With a Sunday week start and INTERVAL=2, the active weeks are shifted so Sunday instances land in the skipped week.
Weekly BYDAY expansion honouring the week-start day: interval step · case 01
An every-other-week series produces instances in every week.
Weekly BYDAY expansion honouring the week-start day: interval step · case 02
An every-other-week series produces instances in every week.
Weekly BYDAY expansion honouring the week-start day: interval step · case 03
An every-other-week series produces instances in every week.
Weekly BYDAY expansion honouring the week-start day: interval step · case 04
An every-other-week series produces instances in every week.
Weekly BYDAY expansion honouring the week-start day: interval step · case 05
An every-other-week series produces instances in every week.
Weekly BYDAY expansion honouring the week-start day: in week order · case 01
With WKST=SU a Sunday instance is emitted after later weekdays, so COUNT keeps the wrong instances.
Weekly BYDAY expansion honouring the week-start day: in week order · case 02
With WKST=SU a Sunday instance is emitted after later weekdays, so COUNT keeps the wrong instances.
Weekly BYDAY expansion honouring the week-start day: in week order · case 03
With WKST=SU a Sunday instance is emitted after later weekdays, so COUNT keeps the wrong instances.
Weekly BYDAY expansion honouring the week-start day: in week order · case 04
With WKST=SU a Sunday instance is emitted after later weekdays, so COUNT keeps the wrong instances.
Weekly BYDAY expansion honouring the week-start day: in week order · case 05
With WKST=SU a Sunday instance is emitted after later weekdays, so COUNT keeps the wrong instances.
Weekly BYDAY expansion honouring the week-start day: before start · case 01
Days of the first week that precede dtstart are reported as instances.
Weekly BYDAY expansion honouring the week-start day: before start · case 02
Days of the first week that precede dtstart are reported as instances.
Weekly BYDAY expansion honouring the week-start day: before start · case 03
Days of the first week that precede dtstart are reported as instances.
Weekly BYDAY expansion honouring the week-start day: before start · case 04
Days of the first week that precede dtstart are reported as instances.
Weekly BYDAY expansion honouring the week-start day: before start · case 05
Days of the first week that precede dtstart are reported as instances.
Weekly BYDAY expansion honouring the week-start day: dtstart seeding · case 01
A dtstart that is not a listed weekday is emitted as an extra first instance and consumes COUNT.
Weekly BYDAY expansion honouring the week-start day: dtstart seeding · case 02
A dtstart that is not a listed weekday is emitted as an extra first instance and consumes COUNT.
Weekly BYDAY expansion honouring the week-start day: dtstart seeding · case 03
A dtstart that is not a listed weekday is emitted as an extra first instance and consumes COUNT.
Weekly BYDAY expansion honouring the week-start day: dtstart seeding · case 04
A dtstart that is not a listed weekday is emitted as an extra first instance and consumes COUNT.
Weekly BYDAY expansion honouring the week-start day: dtstart seeding · case 05
A dtstart that is not a listed weekday is emitted as an extra first instance and consumes COUNT.
Monthly BYMONTHDAY expansion with negative and invalid days: year carry · case 01
A series that crosses December reports January instances in the previous year.
Monthly BYMONTHDAY expansion with negative and invalid days: year carry · case 02
A series that crosses December reports January instances in the previous year.
Monthly BYMONTHDAY expansion with negative and invalid days: year carry · case 03
A series that crosses December reports January instances in the previous year.
Monthly BYMONTHDAY expansion with negative and invalid days: year carry · case 04
A series that crosses December reports January instances in the previous year.
Monthly BYMONTHDAY expansion with negative and invalid days: year carry · case 05
A series that crosses December reports January instances in the previous year.
Monthly BYMONTHDAY expansion with negative and invalid days: negative day · case 01
BYMONTHDAY=-1 produces the second-to-last day of each month.
Monthly BYMONTHDAY expansion with negative and invalid days: negative day · case 02
BYMONTHDAY=-1 produces the second-to-last day of each month.
Monthly BYMONTHDAY expansion with negative and invalid days: negative day · case 03
BYMONTHDAY=-1 produces the second-to-last day of each month.
Monthly BYMONTHDAY expansion with negative and invalid days: negative day · case 04
BYMONTHDAY=-1 produces the second-to-last day of each month.
Monthly BYMONTHDAY expansion with negative and invalid days: negative day · case 05
BYMONTHDAY=-1 produces the second-to-last day of each month.
Monthly BYMONTHDAY expansion with negative and invalid days: invalid day policy · case 01
BYMONTHDAY=31 yields February 28 and April 30 instead of skipping those months.
Monthly BYMONTHDAY expansion with negative and invalid days: invalid day policy · case 02
BYMONTHDAY=31 yields February 28 and April 30 instead of skipping those months.
Monthly BYMONTHDAY expansion with negative and invalid days: invalid day policy · case 03
BYMONTHDAY=31 yields February 28 and April 30 instead of skipping those months.
Monthly BYMONTHDAY expansion with negative and invalid days: invalid day policy · case 04
BYMONTHDAY=31 yields February 28 and April 30 instead of skipping those months.
Monthly BYMONTHDAY expansion with negative and invalid days: invalid day policy · case 05
BYMONTHDAY=31 yields February 28 and April 30 instead of skipping those months.
Monthly BYMONTHDAY expansion with negative and invalid days: dedupe coinciding · case 01
BYMONTHDAY=31,-1 emits the 31st twice in long months.
Monthly BYMONTHDAY expansion with negative and invalid days: dedupe coinciding · case 02
BYMONTHDAY=31,-1 emits the 31st twice in long months.
Monthly BYMONTHDAY expansion with negative and invalid days: dedupe coinciding · case 03
BYMONTHDAY=31,-1 emits the 31st twice in long months.
Monthly BYMONTHDAY expansion with negative and invalid days: dedupe coinciding · case 04
BYMONTHDAY=31,-1 emits the 31st twice in long months.
Monthly BYMONTHDAY expansion with negative and invalid days: dedupe coinciding · case 05
BYMONTHDAY=31,-1 emits the 31st twice in long months.
Monthly BYMONTHDAY expansion with negative and invalid days: first month filter · case 01
Days of the first month that precede dtstart are emitted.
Monthly BYMONTHDAY expansion with negative and invalid days: first month filter · case 02
Days of the first month that precede dtstart are emitted.
Monthly BYMONTHDAY expansion with negative and invalid days: first month filter · case 03
Days of the first month that precede dtstart are emitted.
Monthly BYMONTHDAY expansion with negative and invalid days: first month filter · case 04
Days of the first month that precede dtstart are emitted.
Monthly BYMONTHDAY expansion with negative and invalid days: first month filter · case 05
Days of the first month that precede dtstart are emitted.
Monthly ordinal BYDAY such as 2TU or -1FR: first offset · case 01
The second Tuesday is computed on the wrong date in months that do not begin on Tuesday.
Monthly ordinal BYDAY such as 2TU or -1FR: first offset · case 02
The second Tuesday is computed on the wrong date in months that do not begin on Tuesday.
Monthly ordinal BYDAY such as 2TU or -1FR: first offset · case 03
The second Tuesday is computed on the wrong date in months that do not begin on Tuesday.
Monthly ordinal BYDAY such as 2TU or -1FR: first offset · case 04
The second Tuesday is computed on the wrong date in months that do not begin on Tuesday.
Monthly ordinal BYDAY such as 2TU or -1FR: first offset · case 05
The second Tuesday is computed on the wrong date in months that do not begin on Tuesday.
Monthly ordinal BYDAY such as 2TU or -1FR: last offset · case 01
The last Friday is placed on a non-Friday in most months.
Monthly ordinal BYDAY such as 2TU or -1FR: last offset · case 02
The last Friday is placed on a non-Friday in most months.
Monthly ordinal BYDAY such as 2TU or -1FR: last offset · case 03
The last Friday is placed on a non-Friday in most months.
Monthly ordinal BYDAY such as 2TU or -1FR: last offset · case 04
The last Friday is placed on a non-Friday in most months.
Monthly ordinal BYDAY such as 2TU or -1FR: last offset · case 05
The last Friday is placed on a non-Friday in most months.
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 ↗