A bug in the register allocator which would cause GHC to crash during compilation has been fixed (issue #9155).

A handful of bugs in the pattern synonyms implementation have been fixed (issues #9161, #8966, #9023, #9175).

A bug in runtime system which would cause tryReadMVar to deadlock has been fixed (issue #9148).

A segmentation fault for compiled programs using makeStableName has been fixed (issue #9078).

A bugfix in the runtime system that could cause a segmentation fault has now been fixed (issue #9045).

A bug in the code generator that could cause segmentation faults has been fixed (issue #9001).

A bug in the code generator that could cause segmentation faults has been fixed (issue #9045).

A bug which caused gcc to error when compiling large assembly source files has been fixed (issue #8768).

A bug which caused a performance regression in the new `Typeable` implementation (due to recomputation of known values) has been fixed (issue #9203).

Several memory leaks and bugs in the runtime system and C libraries have been fixed. These issues were found using Coverity Scan.

A bug which caused the runtime system to uninstall signal handlers when they were not installed was fixed (issue #9068).

A bug which could result in programs using all available memory, due to a regression in the Read instance for Data.Fixed.Pico has been fixed (issue #9231).

The libraries haskeline, xhtml, terminfo, transformers, and haskeline are now exported and registered in the package database. They previously shipped with GHC but were not registered, leading to errors where shared objects could be overwritten. (issue #8919).