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
Delimited empty fields vanish · case 01
Delimited empty fields vanish.
Delimited empty fields vanish · case 02
Delimited empty fields vanish.
Delimited empty fields vanish · case 03
Delimited empty fields vanish.
Delimited empty fields vanish · case 04
Delimited empty fields vanish.
Delimited empty fields vanish · case 05
Delimited empty fields vanish.
A terminal line break invents a blank record · case 01
A terminal line break invents a blank record.
A terminal line break invents a blank record · case 02
A terminal line break invents a blank record.
A terminal line break invents a blank record · case 03
A terminal line break invents a blank record.
A terminal line break invents a blank record · case 04
A terminal line break invents a blank record.
A terminal line break invents a blank record · case 05
A terminal line break invents a blank record.
Line terminators lose their original spelling · case 01
Line terminators lose their original spelling.
Line terminators lose their original spelling · case 02
Line terminators lose their original spelling.
Line terminators lose their original spelling · case 03
Line terminators lose their original spelling.
Line terminators lose their original spelling · case 04
Line terminators lose their original spelling.
Line terminators lose their original spelling · case 05
Line terminators lose their original spelling.
Tabs expand without considering current column · case 01
Tabs expand without considering current column.
Tabs expand without considering current column · case 02
Tabs expand without considering current column.
Tabs expand without considering current column · case 03
Tabs expand without considering current column.
Tabs expand without considering current column · case 04
Tabs expand without considering current column.
Tabs expand without considering current column · case 05
Tabs expand without considering current column.
Substring frequency counts overlapping matches · case 01
Substring frequency counts overlapping matches.
Substring frequency counts overlapping matches · case 02
Substring frequency counts overlapping matches.
Substring frequency counts overlapping matches · case 03
Substring frequency counts overlapping matches.
Substring frequency counts overlapping matches · case 04
Substring frequency counts overlapping matches.
Substring frequency counts overlapping matches · case 05
Substring frequency counts overlapping matches.
Empty-pattern replacement misses text boundaries · case 01
Empty-pattern replacement misses text boundaries.
Empty-pattern replacement misses text boundaries · case 02
Empty-pattern replacement misses text boundaries.
Empty-pattern replacement misses text boundaries · case 03
Empty-pattern replacement misses text boundaries.
Empty-pattern replacement misses text boundaries · case 04
Empty-pattern replacement misses text boundaries.
Empty-pattern replacement misses text boundaries · case 05
Empty-pattern replacement misses text boundaries.
A bounded replacement modifies every occurrence · case 01
A bounded replacement modifies every occurrence.
A bounded replacement modifies every occurrence · case 02
A bounded replacement modifies every occurrence.
A bounded replacement modifies every occurrence · case 03
A bounded replacement modifies every occurrence.
A bounded replacement modifies every occurrence · case 04
A bounded replacement modifies every occurrence.
A bounded replacement modifies every occurrence · case 05
A bounded replacement modifies every occurrence.
Character translation cannot expand or delete · case 01
Character translation cannot expand or delete.
Character translation cannot expand or delete · case 02
Character translation cannot expand or delete.
Character translation cannot expand or delete · case 03
Character translation cannot expand or delete.
Character translation cannot expand or delete · case 04
Character translation cannot expand or delete.
Character translation cannot expand or delete · case 05
Character translation cannot expand or delete.
Zero padding precedes the sign · case 01
Zero padding precedes the sign.
Zero padding precedes the sign · case 02
Zero padding precedes the sign.
Zero padding precedes the sign · case 03
Zero padding precedes the sign.
Zero padding precedes the sign · case 04
Zero padding precedes the sign.
Zero padding precedes the sign · case 05
Zero padding precedes the sign.
Odd center padding goes to the wrong side · case 01
Odd center padding goes to the wrong side.
Odd center padding goes to the wrong side · case 02
Odd center padding goes to the wrong side.
Odd center padding goes to the wrong side · case 03
Odd center padding goes to the wrong side.
Odd center padding goes to the wrong side · case 04
Odd center padding goes to the wrong side.
Odd center padding goes to the wrong side · case 05
Odd center padding goes to the wrong side.
Protocol trimming erases significant Unicode whitespace · case 01
Protocol trimming erases significant Unicode whitespace.
Protocol trimming erases significant Unicode whitespace · case 02
Protocol trimming erases significant Unicode whitespace.
Protocol trimming erases significant Unicode whitespace · case 03
Protocol trimming erases significant Unicode whitespace.
Protocol trimming erases significant Unicode whitespace · case 04
Protocol trimming erases significant Unicode whitespace.
Protocol trimming erases significant Unicode whitespace · case 05
Protocol trimming erases significant Unicode whitespace.
Indent removal destroys relative indentation · case 01
Indent removal destroys relative indentation.
Indent removal destroys relative indentation · case 02
Indent removal destroys relative indentation.
Indent removal destroys relative indentation · case 03
Indent removal destroys relative indentation.
Indent removal destroys relative indentation · case 04
Indent removal destroys relative indentation.
Indent removal destroys relative indentation · case 05
Indent removal destroys relative indentation.
A blank line receives an unwanted prefix · case 01
A blank line receives an unwanted prefix.
A blank line receives an unwanted prefix · case 02
A blank line receives an unwanted prefix.
A blank line receives an unwanted prefix · case 03
A blank line receives an unwanted prefix.
A blank line receives an unwanted prefix · case 04
A blank line receives an unwanted prefix.
A blank line receives an unwanted prefix · case 05
A blank line receives an unwanted prefix.
A shortened label cuts through a word · case 01
A shortened label cuts through a word.
A shortened label cuts through a word · case 02
A shortened label cuts through a word.
A shortened label cuts through a word · case 03
A shortened label cuts through a word.
A shortened label cuts through a word · case 04
A shortened label cuts through a word.
A shortened label cuts through a word · case 05
A shortened label cuts through a word.
Non-ASCII diagnostic characters remain literal · case 01
Non-ASCII diagnostic characters remain literal.
Non-ASCII diagnostic characters remain literal · case 02
Non-ASCII diagnostic characters remain literal.
Non-ASCII diagnostic characters remain literal · case 03
Non-ASCII diagnostic characters remain literal.
Non-ASCII diagnostic characters remain literal · case 04
Non-ASCII diagnostic characters remain literal.
Non-ASCII diagnostic characters remain literal · case 05
Non-ASCII diagnostic characters remain literal.
A literal search term executes regex syntax · case 01
A literal search term executes regex syntax.
A literal search term executes regex syntax · case 02
A literal search term executes regex syntax.
A literal search term executes regex syntax · case 03
A literal search term executes regex syntax.
A literal search term executes regex syntax · case 04
A literal search term executes regex syntax.
A literal search term executes regex syntax · case 05
A literal search term executes regex syntax.
A token validator accepts a suffix after a match · case 01
A token validator accepts a suffix after a match.
A token validator accepts a suffix after a match · case 02
A token validator accepts a suffix after a match.
A token validator accepts a suffix after a match · case 03
A token validator accepts a suffix after a match.
A token validator accepts a suffix after a match · case 04
A token validator accepts a suffix after a match.
A token validator accepts a suffix after a match · case 05
A token validator accepts a suffix after a match.
A multiline quoted block stops at a newline · case 01
A multiline quoted block stops at a newline.
A multiline quoted block stops at a newline · case 02
A multiline quoted block stops at a newline.
A multiline quoted block stops at a newline · case 03
A multiline quoted block stops at a newline.
A multiline quoted block stops at a newline · case 04
A multiline quoted block stops at a newline.
A multiline quoted block stops at a newline · case 05
A multiline quoted block stops at a newline.
One tag match consumes neighboring tags · case 01
One tag match consumes neighboring tags.
One tag match consumes neighboring tags · case 02
One tag match consumes neighboring tags.
One tag match consumes neighboring tags · case 03
One tag match consumes neighboring tags.
One tag match consumes neighboring tags · case 04
One tag match consumes neighboring tags.
One tag match consumes neighboring tags · case 05
One tag match consumes neighboring tags.
Split delimiters unexpectedly enter the result · case 01
Split delimiters unexpectedly enter the result.
Split delimiters unexpectedly enter the result · case 02
Split delimiters unexpectedly enter the result.
Split delimiters unexpectedly enter the result · case 03
Split delimiters unexpectedly enter the result.
Split delimiters unexpectedly enter the result · case 04
Split delimiters unexpectedly enter the result.
Split delimiters unexpectedly enter the result · case 05
Split delimiters unexpectedly enter the result.
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 ↗