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
Free tickets counted against total travellers · case 01
A group of 15 receives a free ticket although only 14 would then be paying.
Free tickets counted against total travellers · case 02
A group of 15 receives a free ticket although only 14 would then be paying.
Free tickets counted against total travellers · case 03
A group of 15 receives a free ticket although only 14 would then be paying.
Free tickets counted against total travellers · case 04
A group of 15 receives a free ticket although only 14 would then be paying.
Free tickets counted against total travellers · case 05
A group of 15 receives a free ticket although only 14 would then be paying.
Group exactly at the minimum size denied the group fare · case 01
Ten travellers booking a ten-minimum group fare pay the full fare.
Group exactly at the minimum size denied the group fare · case 02
Ten travellers booking a ten-minimum group fare pay the full fare.
Group exactly at the minimum size denied the group fare · case 03
Ten travellers booking a ten-minimum group fare pay the full fare.
Group exactly at the minimum size denied the group fare · case 04
Ten travellers booking a ten-minimum group fare pay the full fare.
Group exactly at the minimum size denied the group fare · case 05
Ten travellers booking a ten-minimum group fare pay the full fare.
Group discount rounded only on the total · case 01
The group total differs by a few cents from the per-passenger fares printed on each ticket.
Group discount rounded only on the total · case 02
The group total differs by a few cents from the per-passenger fares printed on each ticket.
Group discount rounded only on the total · case 03
The group total differs by a few cents from the per-passenger fares printed on each ticket.
Group discount rounded only on the total · case 04
The group total differs by a few cents from the per-passenger fares printed on each ticket.
Group discount rounded only on the total · case 05
The group total differs by a few cents from the per-passenger fares printed on each ticket.
Parties below the group minimum receive conductor tickets · case 01
A 12-person party on a 20-minimum group fare gets two free tickets.
Parties below the group minimum receive conductor tickets · case 02
A 12-person party on a 20-minimum group fare gets two free tickets.
Parties below the group minimum receive conductor tickets · case 03
A 12-person party on a 20-minimum group fare gets two free tickets.
Parties below the group minimum receive conductor tickets · case 04
A 12-person party on a 20-minimum group fare gets two free tickets.
Parties below the group minimum receive conductor tickets · case 05
A 12-person party on a 20-minimum group fare gets two free tickets.
A connection of exactly 24 hours counted as a stopover · case 01
An international connection of exactly 24 hours consumes the stopover allowance.
A connection of exactly 24 hours counted as a stopover · case 02
An international connection of exactly 24 hours consumes the stopover allowance.
A connection of exactly 24 hours counted as a stopover · case 03
An international connection of exactly 24 hours consumes the stopover allowance.
A connection of exactly 24 hours counted as a stopover · case 04
An international connection of exactly 24 hours consumes the stopover allowance.
A connection of exactly 24 hours counted as a stopover · case 05
An international connection of exactly 24 hours consumes the stopover allowance.
Domestic stopover limit applied from the onward segment only · case 01
A domestic-to-international six-hour connection is counted as a stopover.
Domestic stopover limit applied from the onward segment only · case 02
A domestic-to-international six-hour connection is counted as a stopover.
Domestic stopover limit applied from the onward segment only · case 03
A domestic-to-international six-hour connection is counted as a stopover.
Domestic stopover limit applied from the onward segment only · case 04
A domestic-to-international six-hour connection is counted as a stopover.
Domestic stopover limit applied from the onward segment only · case 05
A domestic-to-international six-hour connection is counted as a stopover.
Connection time measured from the inbound departure · case 01
Long-haul flights followed by short connections are counted as stopovers.
Connection time measured from the inbound departure · case 02
Long-haul flights followed by short connections are counted as stopovers.
Connection time measured from the inbound departure · case 03
Long-haul flights followed by short connections are counted as stopovers.
Connection time measured from the inbound departure · case 04
Long-haul flights followed by short connections are counted as stopovers.
Connection time measured from the inbound departure · case 05
Long-haul flights followed by short connections are counted as stopovers.
Transfers counted per flight segment · case 01
A nonstop flight reports one transfer.
Transfers counted per flight segment · case 02
A nonstop flight reports one transfer.
Transfers counted per flight segment · case 03
A nonstop flight reports one transfer.
Transfers counted per flight segment · case 04
A nonstop flight reports one transfer.
Transfers counted per flight segment · case 05
A nonstop flight reports one transfer.
One year of validity counted as 365 days · case 01
Tickets whose validity spans 29 February expire a day early.
One year of validity counted as 365 days · case 02
Tickets whose validity spans 29 February expire a day early.
One year of validity counted as 365 days · case 03
Tickets whose validity spans 29 February expire a day early.
One year of validity counted as 365 days · case 04
Tickets whose validity spans 29 February expire a day early.
One year of validity counted as 365 days · case 05
Tickets whose validity spans 29 February expire a day early.
Validity stays anchored on issue after travel begins · case 01
A ticket first used three months after issue expires three months early.
Validity stays anchored on issue after travel begins · case 02
A ticket first used three months after issue expires three months early.
Validity stays anchored on issue after travel begins · case 03
A ticket first used three months after issue expires three months early.
Validity stays anchored on issue after travel begins · case 04
A ticket first used three months after issue expires three months early.
Validity stays anchored on issue after travel begins · case 05
A ticket first used three months after issue expires three months early.
Leap-day validity extended to 1 March · case 01
A ticket issued on 29 February remains valid on 1 March of the next year.
Leap-day validity extended to 1 March · case 02
A ticket issued on 29 February remains valid on 1 March of the next year.
Leap-day validity extended to 1 March · case 03
A ticket issued on 29 February remains valid on 1 March of the next year.
Leap-day validity extended to 1 March · case 04
A ticket issued on 29 February remains valid on 1 March of the next year.
Leap-day validity extended to 1 March · case 05
A ticket issued on 29 February remains valid on 1 March of the next year.
Travel on the last valid day treated as expired · case 01
Starting travel exactly one year after issue is refused.
Travel on the last valid day treated as expired · case 02
Starting travel exactly one year after issue is refused.
Travel on the last valid day treated as expired · case 03
Starting travel exactly one year after issue is refused.
Travel on the last valid day treated as expired · case 04
Starting travel exactly one year after issue is refused.
Travel on the last valid day treated as expired · case 05
Starting travel exactly one year after issue is refused.
Cancellation fee eats into refundable taxes · case 01
A cheap ticket with a large penalty refunds less than its refundable government taxes.
Cancellation fee eats into refundable taxes · case 02
A cheap ticket with a large penalty refunds less than its refundable government taxes.
Cancellation fee eats into refundable taxes · case 03
A cheap ticket with a large penalty refunds less than its refundable government taxes.
Cancellation fee eats into refundable taxes · case 04
A cheap ticket with a large penalty refunds less than its refundable government taxes.
Cancellation fee eats into refundable taxes · case 05
A cheap ticket with a large penalty refunds less than its refundable government taxes.
Taxes on flown coupons refunded · case 01
Partially used tickets refund departure taxes for sectors already flown.
Taxes on flown coupons refunded · case 02
Partially used tickets refund departure taxes for sectors already flown.
Taxes on flown coupons refunded · case 03
Partially used tickets refund departure taxes for sectors already flown.
Taxes on flown coupons refunded · case 04
Partially used tickets refund departure taxes for sectors already flown.
Taxes on flown coupons refunded · case 05
Partially used tickets refund departure taxes for sectors already flown.
Non-refundable charges refunded on fully unused tickets · case 01
An unused ticket refunds its non-refundable carrier-imposed charge.
Non-refundable charges refunded on fully unused tickets · case 02
An unused ticket refunds its non-refundable carrier-imposed charge.
Non-refundable charges refunded on fully unused tickets · case 03
An unused ticket refunds its non-refundable carrier-imposed charge.
Non-refundable charges refunded on fully unused tickets · case 04
An unused ticket refunds its non-refundable carrier-imposed charge.
Non-refundable charges refunded on fully unused tickets · case 05
An unused ticket refunds its non-refundable carrier-imposed charge.
Used-fare deduction applied to unused tickets · case 01
An unused ticket carrying a stale used-fare estimate refunds less than it should.
Used-fare deduction applied to unused tickets · case 02
An unused ticket carrying a stale used-fare estimate refunds less than it should.
Used-fare deduction applied to unused tickets · case 03
An unused ticket carrying a stale used-fare estimate refunds less than it should.
Used-fare deduction applied to unused tickets · case 04
An unused ticket carrying a stale used-fare estimate refunds less than it should.
Used-fare deduction applied to unused tickets · case 05
An unused ticket carrying a stale used-fare estimate refunds less than it should.
Inbound surcharge decided by the outbound date · case 01
A weekend return after a weekday departure is not surcharged, while a weekday return after a weekend departure is.
Inbound surcharge decided by the outbound date · case 02
A weekend return after a weekday departure is not surcharged, while a weekday return after a weekend departure is.
Inbound surcharge decided by the outbound date · case 03
A weekend return after a weekday departure is not surcharged, while a weekday return after a weekend departure is.
Inbound surcharge decided by the outbound date · case 04
A weekend return after a weekday departure is not surcharged, while a weekday return after a weekend departure is.
Inbound surcharge decided by the outbound date · case 05
A weekend return after a weekday departure is not surcharged, while a weekday return after a weekend departure is.
Outbound-only surcharge rule charged on return · case 01
Fares with an OUTBOUND rule add a second weekend surcharge on the return.
Outbound-only surcharge rule charged on return · case 02
Fares with an OUTBOUND rule add a second weekend surcharge on the return.
Outbound-only surcharge rule charged on return · case 03
Fares with an OUTBOUND rule add a second weekend surcharge on the return.
Outbound-only surcharge rule charged on return · case 04
Fares with an OUTBOUND rule add a second weekend surcharge on the return.
Outbound-only surcharge rule charged on return · case 05
Fares with an OUTBOUND rule add a second weekend surcharge on the return.
Only the outbound surcharge multiplied by passengers · case 01
A family of four is charged four outbound weekend surcharges but a single inbound one.
Only the outbound surcharge multiplied by passengers · case 02
A family of four is charged four outbound weekend surcharges but a single inbound one.
Only the outbound surcharge multiplied by passengers · case 03
A family of four is charged four outbound weekend surcharges but a single inbound one.
Only the outbound surcharge multiplied by passengers · case 04
A family of four is charged four outbound weekend surcharges but a single inbound one.
Only the outbound surcharge multiplied by passengers · case 05
A family of four is charged four outbound weekend surcharges but a single inbound one.
Half fares rounded once on the combined total · case 01
Two odd round-trip fares combine one unit cheaper than their rounded halves.
Half fares rounded once on the combined total · case 02
Two odd round-trip fares combine one unit cheaper than their rounded halves.
Half fares rounded once on the combined total · case 03
Two odd round-trip fares combine one unit cheaper than their rounded halves.
Half fares rounded once on the combined total · case 04
Two odd round-trip fares combine one unit cheaper than their rounded halves.
Half fares rounded once on the combined total · case 05
Two odd round-trip fares combine one unit cheaper than their rounded halves.
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 ↗