D 语言 2.089.1 版本是一个修复版本，上个大版本 2.089.0 存在一些改进后的不兼容问题得到了修复，提升了稳定性。

DMD 编译器改进：

1. Bugzilla 15069: [REG2.064] nonsense struct template instantiations still compile
2. Bugzilla 19884: [regression] Error: alias op = op; cannot alias itself, use a qualified name to create an overload set
3. Bugzilla 20348: [Reg 2.089.0-rc.1] Bad debug info for enum forward references
4. Bugzilla 20349: [REG2.087] ICE with sqrt
5. Bugzilla 20376: @disable this(ref return scope Foo rhs) enables broken binaries (out-of-bounds access)
6. Bugzilla 20388: Parse error when compiling lambdas in mixins as template parameters
7. Bugzilla 20416: [Regression 2.073.2] compiler complains about escaping reference in certain cases
8. Bugzilla 20420: [REG2.067] inlining error with a valid function

DMD 编译器问题修复：

1. Bugzilla 20092: void[1] auto slicing makes the compiler hang
2. Bugzilla 20253: bad debug line info for function without epilog
3. Bugzilla 20264: ICE on illegal cast to vector.
4. Bugzilla 20280: Compiler segfault when building two small files
5. Bugzilla 20366: CTFE foreach_reverse on array with utf characters crashes compiler
6. Bugzilla 20431: Allow a Mixin Type to resolve to an expression where it makes sense
7. Bugzilla 20441: Wrong code with -O -fPIC and pointer subtraction

DMD 编译器增强：

1. Bugzilla 20356: exceeding template expansion limits

标准库修改：

1. Bugzilla 20054: getSymbolsByUDA no longer works on modules
2. Bugzilla 20350: JSONType deprecations should be undeprecated
3. Bugzilla 20354: interface is not supported by CanCAS in core.internal.atomic

运行时修改：

1. Bugzilla 20438: [Reg 2.086] GC: memory not reusable when calling GC.collect after GC.free

运行时 BUG 修复：

1. Bugzilla 20355: undefined identifier U in core.atomic

工具 BUG：

1. Bugzilla 20386: Test extractor shouldn't emit unit tests, but regular functions for @betterC tests