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 ↗A RECORD OF WHAT WENT WRONG
Browse the archive / 97840
A calendar year is paired with a week from the previous ISO year · case 01
Dates near New Year receive a week number from one ISO year and a year label from another.
A calendar year is paired with a week from the previous ISO year · case 02
Dates near New Year receive a week number from one ISO year and a year label from another.
A calendar year is paired with a week from the previous ISO year · case 03
Dates near New Year receive a week number from one ISO year and a year label from another.
A calendar year is paired with a week from the previous ISO year · case 04
Dates near New Year receive a week number from one ISO year and a year label from another.
A calendar year is paired with a week from the previous ISO year · case 05
Dates near New Year receive a week number from one ISO year and a year label from another.
Sorting local timestamp text reverses the order of absolute instants · case 01
An event with a later wall-clock reading is placed after an event that actually occurred later in UTC.
Sorting local timestamp text reverses the order of absolute instants · case 02
An event with a later wall-clock reading is placed after an event that actually occurred later in UTC.
Sorting local timestamp text reverses the order of absolute instants · case 03
An event with a later wall-clock reading is placed after an event that actually occurred later in UTC.
Sorting local timestamp text reverses the order of absolute instants · case 04
An event with a later wall-clock reading is placed after an event that actually occurred later in UTC.
Sorting local timestamp text reverses the order of absolute instants · case 05
An event with a later wall-clock reading is placed after an event that actually occurred later in UTC.
Duration formatting wraps elapsed hours at midnight · case 01
A multi-day duration loses its day component, and a negative duration looks like a positive time of day.
Duration formatting wraps elapsed hours at midnight · case 02
A multi-day duration loses its day component, and a negative duration looks like a positive time of day.
Duration formatting wraps elapsed hours at midnight · case 03
A multi-day duration loses its day component, and a negative duration looks like a positive time of day.
Duration formatting wraps elapsed hours at midnight · case 04
A multi-day duration loses its day component, and a negative duration looks like a positive time of day.
Duration formatting wraps elapsed hours at midnight · case 05
A multi-day duration loses its day component, and a negative duration looks like a positive time of day.
A weighted total is divided by the number of records · case 01
Changing the scale of weights changes the result, or unequal-weight observations are treated as equally influential.
A weighted total is divided by the number of records · case 02
Changing the scale of weights changes the result, or unequal-weight observations are treated as equally influential.
A weighted total is divided by the number of records · case 03
Changing the scale of weights changes the result, or unequal-weight observations are treated as equally influential.
A weighted total is divided by the number of records · case 04
Changing the scale of weights changes the result, or unequal-weight observations are treated as equally influential.
A weighted total is divided by the number of records · case 05
Changing the scale of weights changes the result, or unequal-weight observations are treated as equally influential.
Large cancelling terms erase a small summand · case 01
A mathematically nonzero residual disappears when large positive and negative terms cancel.
Large cancelling terms erase a small summand · case 02
A mathematically nonzero residual disappears when large positive and negative terms cancel.
Large cancelling terms erase a small summand · case 03
A mathematically nonzero residual disappears when large positive and negative terms cancel.
Large cancelling terms erase a small summand · case 04
A mathematically nonzero residual disappears when large positive and negative terms cancel.
Large cancelling terms erase a small summand · case 05
A mathematically nonzero residual disappears when large positive and negative terms cancel.
Subtracting two large moments destroys a small variance · case 01
A nonconstant sample reports zero or an inaccurate variance after its mean is shifted far from zero.
Subtracting two large moments destroys a small variance · case 02
A nonconstant sample reports zero or an inaccurate variance after its mean is shifted far from zero.
Subtracting two large moments destroys a small variance · case 03
A nonconstant sample reports zero or an inaccurate variance after its mean is shifted far from zero.
Subtracting two large moments destroys a small variance · case 04
A nonconstant sample reports zero or an inaccurate variance after its mean is shifted far from zero.
Subtracting two large moments destroys a small variance · case 05
A nonconstant sample reports zero or an inaccurate variance after its mean is shifted far from zero.
Rescaling integer ticks loses precision in an intermediate step · case 01
Large counters change by several ticks after a float conversion, or fractional source units disappear before multiplication.
Rescaling integer ticks loses precision in an intermediate step · case 02
Large counters change by several ticks after a float conversion, or fractional source units disappear before multiplication.
Rescaling integer ticks loses precision in an intermediate step · case 03
Large counters change by several ticks after a float conversion, or fractional source units disappear before multiplication.
Rescaling integer ticks loses precision in an intermediate step · case 04
Large counters change by several ticks after a float conversion, or fractional source units disappear before multiplication.
Rescaling integer ticks loses precision in an intermediate step · case 05
Large counters change by several ticks after a float conversion, or fractional source units disappear before multiplication.
Percentile interpolation uses unsorted observation positions · case 01
A percentile depends on input order or jumps to a nearest-rank value instead of the specified interpolated value.
Percentile interpolation uses unsorted observation positions · case 02
A percentile depends on input order or jumps to a nearest-rank value instead of the specified interpolated value.
Percentile interpolation uses unsorted observation positions · case 03
A percentile depends on input order or jumps to a nearest-rank value instead of the specified interpolated value.
Percentile interpolation uses unsorted observation positions · case 04
A percentile depends on input order or jumps to a nearest-rank value instead of the specified interpolated value.
Percentile interpolation uses unsorted observation positions · case 05
A percentile depends on input order or jumps to a nearest-rank value instead of the specified interpolated value.
A positive-only tie rule rounds negative halves toward zero · case 01
Exact midpoint values receive even rounding or asymmetric rounding instead of the required away-from-zero result.
A positive-only tie rule rounds negative halves toward zero · case 02
Exact midpoint values receive even rounding or asymmetric rounding instead of the required away-from-zero result.
A positive-only tie rule rounds negative halves toward zero · case 03
Exact midpoint values receive even rounding or asymmetric rounding instead of the required away-from-zero result.
A positive-only tie rule rounds negative halves toward zero · case 04
Exact midpoint values receive even rounding or asymmetric rounding instead of the required away-from-zero result.
A positive-only tie rule rounds negative halves toward zero · case 05
Exact midpoint values receive even rounding or asymmetric rounding instead of the required away-from-zero result.
A geometric-mean product overflows although the result is finite · case 01
Multiplying observations produces infinity or zero even when their geometric mean is a representable positive number.
A geometric-mean product overflows although the result is finite · case 02
Multiplying observations produces infinity or zero even when their geometric mean is a representable positive number.
A geometric-mean product overflows although the result is finite · case 03
Multiplying observations produces infinity or zero even when their geometric mean is a representable positive number.
A geometric-mean product overflows although the result is finite · case 04
Multiplying observations produces infinity or zero even when their geometric mean is a representable positive number.
A geometric-mean product overflows although the result is finite · case 05
Multiplying observations produces infinity or zero even when their geometric mean is a representable positive number.
Activate a joint voting configuration: The old configuration has only a minority · case 01
The joint configuration operation is admitted even though the old configuration has only a minority.
Activate a joint voting configuration: The old configuration has only a minority · case 02
The joint configuration operation is admitted even though the old configuration has only a minority.
Activate a joint voting configuration: The old configuration has only a minority · case 03
The joint configuration operation is admitted even though the old configuration has only a minority.
Activate a joint voting configuration: The old configuration has only a minority · case 04
The joint configuration operation is admitted even though the old configuration has only a minority.
Activate a joint voting configuration: The old configuration has only a minority · case 05
The joint configuration operation is admitted even though the old configuration has only a minority.
Activate a joint voting configuration: The new configuration has only a minority · case 01
The joint configuration operation is admitted even though the new configuration has only a minority.
Activate a joint voting configuration: The new configuration has only a minority · case 02
The joint configuration operation is admitted even though the new configuration has only a minority.
Activate a joint voting configuration: The new configuration has only a minority · case 03
The joint configuration operation is admitted even though the new configuration has only a minority.
Activate a joint voting configuration: The new configuration has only a minority · case 04
The joint configuration operation is admitted even though the new configuration has only a minority.
Activate a joint voting configuration: The new configuration has only a minority · case 05
The joint configuration operation is admitted even though the new configuration has only a minority.
Activate a joint voting configuration: The configuration entry is beyond the committed prefix · case 01
The joint configuration operation is admitted even though the configuration entry is beyond the committed prefix.
Activate a joint voting configuration: The configuration entry is beyond the committed prefix · case 02
The joint configuration operation is admitted even though the configuration entry is beyond the committed prefix.
Activate a joint voting configuration: The configuration entry is beyond the committed prefix · case 03
The joint configuration operation is admitted even though the configuration entry is beyond the committed prefix.
Activate a joint voting configuration: The configuration entry is beyond the committed prefix · case 04
The joint configuration operation is admitted even though the configuration entry is beyond the committed prefix.
Activate a joint voting configuration: The configuration entry is beyond the committed prefix · case 05
The joint configuration operation is admitted even though the configuration entry is beyond the committed prefix.
Activate a joint voting configuration: A second membership change overlaps an unfinalized change · case 01
The joint configuration operation is admitted even though a second membership change overlaps an unfinalized change.
Activate a joint voting configuration: A second membership change overlaps an unfinalized change · case 02
The joint configuration operation is admitted even though a second membership change overlaps an unfinalized change.
Activate a joint voting configuration: A second membership change overlaps an unfinalized change · case 03
The joint configuration operation is admitted even though a second membership change overlaps an unfinalized change.
Activate a joint voting configuration: A second membership change overlaps an unfinalized change · case 04
The joint configuration operation is admitted even though a second membership change overlaps an unfinalized change.
Activate a joint voting configuration: A second membership change overlaps an unfinalized change · case 05
The joint configuration operation is admitted even though a second membership change overlaps an unfinalized change.
Activate a joint voting configuration: A promoted learner lacks the configuration entry · case 01
The joint configuration operation is admitted even though a promoted learner lacks the configuration entry.
Activate a joint voting configuration: A promoted learner lacks the configuration entry · case 02
The joint configuration operation is admitted even though a promoted learner lacks the configuration entry.
Activate a joint voting configuration: A promoted learner lacks the configuration entry · case 03
The joint configuration operation is admitted even though a promoted learner lacks the configuration entry.
Activate a joint voting configuration: A promoted learner lacks the configuration entry · case 04
The joint configuration operation is admitted even though a promoted learner lacks the configuration entry.
Activate a joint voting configuration: A promoted learner lacks the configuration entry · case 05
The joint configuration operation is admitted even though a promoted learner lacks the configuration entry.
Transfer leadership to a chosen voter: Leadership is handed to a learner · case 01
The leader transfer operation is admitted even though leadership is handed to a learner.
Transfer leadership to a chosen voter: Leadership is handed to a learner · case 02
The leader transfer operation is admitted even though leadership is handed to a learner.
Transfer leadership to a chosen voter: Leadership is handed to a learner · case 03
The leader transfer operation is admitted even though leadership is handed to a learner.
Transfer leadership to a chosen voter: Leadership is handed to a learner · case 04
The leader transfer operation is admitted even though leadership is handed to a learner.
Transfer leadership to a chosen voter: Leadership is handed to a learner · case 05
The leader transfer operation is admitted even though leadership is handed to a learner.
Transfer leadership to a chosen voter: The target lacks the leader final log entry · case 01
The leader transfer operation is admitted even though the target lacks the leader final log entry.
Transfer leadership to a chosen voter: The target lacks the leader final log entry · case 02
The leader transfer operation is admitted even though the target lacks the leader final log entry.
Transfer leadership to a chosen voter: The target lacks the leader final log entry · case 03
The leader transfer operation is admitted even though the target lacks the leader final log entry.
Transfer leadership to a chosen voter: The target lacks the leader final log entry · case 04
The leader transfer operation is admitted even though the target lacks the leader final log entry.
Transfer leadership to a chosen voter: The target lacks the leader final log entry · case 05
The leader transfer operation is admitted even though the target lacks the leader final log entry.
Transfer leadership to a chosen voter: A delayed handoff names an obsolete term · case 01
The leader transfer operation is admitted even though a delayed handoff names an obsolete term.
Transfer leadership to a chosen voter: A delayed handoff names an obsolete term · case 02
The leader transfer operation is admitted even though a delayed handoff names an obsolete term.
Transfer leadership to a chosen voter: A delayed handoff names an obsolete term · case 03
The leader transfer operation is admitted even though a delayed handoff names an obsolete term.
Transfer leadership to a chosen voter: A delayed handoff names an obsolete term · case 04
The leader transfer operation is admitted even though a delayed handoff names an obsolete term.
Transfer leadership to a chosen voter: A delayed handoff names an obsolete term · case 05
The leader transfer operation is admitted even though a delayed handoff names an obsolete term.
Transfer leadership to a chosen voter: The handoff arrives after its transfer deadline · case 01
The leader transfer operation is admitted even though the handoff arrives after its transfer deadline.
Transfer leadership to a chosen voter: The handoff arrives after its transfer deadline · case 02
The leader transfer operation is admitted even though the handoff arrives after its transfer deadline.
Transfer leadership to a chosen voter: The handoff arrives after its transfer deadline · case 03
The leader transfer operation is admitted even though the handoff arrives after its transfer deadline.
Transfer leadership to a chosen voter: The handoff arrives after its transfer deadline · case 04
The leader transfer operation is admitted even though the handoff arrives after its transfer deadline.
Transfer leadership to a chosen voter: The handoff arrives after its transfer deadline · case 05
The leader transfer operation is admitted even though the handoff arrives after its transfer deadline.
Transfer leadership to a chosen voter: A transfer races outstanding leader writes · case 01
The leader transfer operation is admitted even though a transfer races outstanding leader writes.
Transfer leadership to a chosen voter: A transfer races outstanding leader writes · case 02
The leader transfer operation is admitted even though a transfer races outstanding leader writes.
Transfer leadership to a chosen voter: A transfer races outstanding leader writes · case 03
The leader transfer operation is admitted even though a transfer races outstanding leader writes.
Transfer leadership to a chosen voter: A transfer races outstanding leader writes · case 04
The leader transfer operation is admitted even though a transfer races outstanding leader writes.
Transfer leadership to a chosen voter: A transfer races outstanding leader writes · case 05
The leader transfer operation is admitted even though a transfer races outstanding leader writes.
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 ↗