Version 2.9.4$$$(released 29 September 2025)$$$$$$Changes:$$$Add new builtin functions for array manipulation: select_from_index_X can slice an array with a non-contiguous set of indices; and concat_index_X can concatenate two arrays along a specified index.$$$Add option type versions of bin packing and cumulatives constraints.$$$Remove bool_xor with two arguments from the FlatZinc builtins. It is never output into FlatZinc by the compiler and violated the rule that FlatZinc builtins are not overloaded (issue 913). Also remove some other duplicates and incorrect overloads from flatzinc_builtins.mzn.$$$Add includes for header files where symbols are required; in order to avoid issues with some compilers.$$$Fix AST string allocation to avoid warnings about writing into unallocated memory.$$$Fix float literal parsing; making it consistent across all platforms (issue 941).$$$$$$Bug fixes:$$$Fix compilation of arrays of arrays when inferred type-inst is var; and pretty-printing of arrays of arrays (issue 942).$$$Fix CSE for empty arrays; which could cause incorrect function overloads to be called (issue 946).$$$Fix a bug in the Constants class that caused the GC to access uninitialised memory (issue 933).$$$Fix a bug in the chain compression algorithm that resulted in incorrectly removing constraints that were not redundant (issue 943).$$$Fix a bug in the nvalue decomposition to also make it work for empty arrays.$$$Fix a bug in the parser that could sometimes cause a crash when parsing invalid syntax (issue 950).$$$Fix a bug in type specialisation that could sometimes lead to a crash (issue 950).$$$Fix a bug where trace_dbg would always get evaluated regardless of the presence of the --debug flag (issue 926).$$$Fix a bug where the argument to --fzn-flags would not be correctly parsed if it also matched a MiniZinc flag (issue 940).$$$Fix bounds computation for division and modulo operations to not abort if the bounds cannot be computed (issue 917).$$$Fix two incorrect comparison functions that could trigger assertions in debug builds (and likely incorrect behaviour in optimised builds).$$$Fix incorrect overloading resolution for polymorphic functions when called with empty set literals as arguments (issue 875).$$$Fix handling of duplicate polymorphic function definitions with empty bodies (issue 875).$$$Fix internal error when accessing out of bounds indices for arrays containing arrays (issue 954).$$$Fix performance of evaluating array comprehensions; which previously could lead to quadratic behaviour in some cases.

Version 2.9.3?$$$(released 23 May 2025)$$$$$$Changes:?$$$Add mzn_max_version_required to enable models to speficy the maximum version of MiniZinc required to run the model (issue 872).$$$$$$Replace use of ptrdiff_t with appropriate unsigned integer type.$$$$$$Clarify documentation example use of boolean extra flags in solver configuration files.$$$$$$Warnings produced in solution checkers are now output as part of the checker message when running in --json-stream mode.$$$$$$Bug fixes:?$$$Fix the rewriting of the multidimensional search annotations to ensure correct coercion of arguments (issue 897).$$$$$$Output location of some errors where the problematic expression previously did not have a location (issue 899).$$$$$$Fix domain computation to avoid variables being moved to the output model when they are constrained (issue 911).$$$$$$Fix output processing to also respect the -o flag when flattening already detects unsatisfiability (issue 908).$$$$$$Report an error when solving a FlatZinc file that does not contain a solve item (issue 907).$$$$$$Pass command line options to the compiler phases earlier to avoid problems with e.g. the --disable-warnings flag (issue 893).$$$$$$Fix incorrect generation of par versions of functions referencing top-level tuples/records containing var fields (issue 919).$$$$$$Fix problem where using an iterator of variable tuple or record types could result in a segfault (issue 901).$$$$$$Fix a problem where an operator such as <= on an optional type would sometimes lead to an internal compiler error (issue 898).$$$$$$Print enum values in stack traces (issue 912).$$$$$$Fix a bug where incompatible overloads could be used when dispatching to more specific versions of functions (issue 905).$$$$$$Fix internal error when constraining the domain of var opt bool variables.$$$$$$Fix record merge operator when evaluated via a field access (issue 892).$$$$$$Update documentation to indicate that the float_ceil; float_floor; and float_round FlatZinc builtins need to be placed in redefinitions-2.7.1.mzn (issue 914).$$$$$$Fix handling of basic standard flags when running .fzn files (issue 920).$$$$$$Fix return type computation for generic functions called with tuple or record types (issue 902).$$$$$$Fix type computation for arrays of tuples/records containing $T members.$$$$$$Fix flattening of anonymous variables of enum type to be correctly bounded.$$$$$$Emit type errors for unsupported usage of anonymous variables in tuples and records.$$$$$$Fix incorrect flattening of in for tuples/records containing optional values (issue 900).

Version 2.9.3?$$$(released 23 May 2025)$$$$$$Changes:?$$$Add mzn_max_version_required to enable models to speficy the maximum version of MiniZinc required to run the model (issue 872).$$$$$$Replace use of ptrdiff_t with appropriate unsigned integer type.$$$$$$Clarify documentation example use of boolean extra flags in solver configuration files.$$$$$$Warnings produced in solution checkers are now output as part of the checker message when running in --json-stream mode.$$$$$$Bug fixes:?$$$Fix the rewriting of the multidimensional search annotations to ensure correct coercion of arguments (issue 897).$$$$$$Output location of some errors where the problematic expression previously did not have a location (issue 899).$$$$$$Fix domain computation to avoid variables being moved to the output model when they are constrained (issue 911).$$$$$$Fix output processing to also respect the -o flag when flattening already detects unsatisfiability (issue 908).$$$$$$Report an error when solving a FlatZinc file that does not contain a solve item (issue 907).$$$$$$Pass command line options to the compiler phases earlier to avoid problems with e.g. the --disable-warnings flag (issue 893).$$$$$$Fix incorrect generation of par versions of functions referencing top-level tuples/records containing var fields (issue 919).$$$$$$Fix problem where using an iterator of variable tuple or record types could result in a segfault (issue 901).$$$$$$Fix a problem where an operator such as <= on an optional type would sometimes lead to an internal compiler error (issue 898).$$$$$$Print enum values in stack traces (issue 912).$$$$$$Fix a bug where incompatible overloads could be used when dispatching to more specific versions of functions (issue 905).$$$$$$Fix internal error when constraining the domain of var opt bool variables.$$$$$$Fix record merge operator when evaluated via a field access (issue 892).$$$$$$Update documentation to indicate that the float_ceil; float_floor; and float_round FlatZinc builtins need to be placed in redefinitions-2.7.1.mzn (issue 914).$$$$$$Fix handling of basic standard flags when running .fzn files (issue 920).$$$$$$Fix return type computation for generic functions called with tuple or record types (issue 902).$$$$$$Fix type computation for arrays of tuples/records containing $T members.$$$$$$Fix flattening of anonymous variables of enum type to be correctly bounded.$$$$$$Emit type errors for unsupported usage of anonymous variables in tuples and records.$$$$$$Fix incorrect flattening of in for tuples/records containing optional values (issue 900).

Version 2.9.2$$$(released 6 March 2025)$$$Bug fixes:$$$Prevent output of and emit warning for invalid statistics in JSON streaming mode.$$$Fix crash in string interpolation (issue 891).$$$Fix row and col functions to use enumerated types instead of int (issue 888).

Version 2.8.7?$$$(released 2 October 2024)$$$$$$Bug fixes:?$$$Fix bug that caused where clauses to be removed from comprehensions.$$$$$$Fix optimisation of Boolean constraints that could sometimes trigger an assertion failure in debug builds (issue 843).