现在我无法在我的文件系统中的任何地方stack new my-project。当我这样做时，我得到
| => stack new my-project
Downloading template "new-template" to create project "my-project" in my-project/ ...
Looking for .cabal or package.yaml files to use to init the project.
Using cabal packages:
- my-project/my-project.cabal
Selecting the best among 12 snapshots...
Downloaded lts-10.2 build plan.
AesonException "Error in $.packages.cassava.constraints.flags['bytestring--lt-0_10_4']: Invalid flag name: \"bytestring--lt-0_10_4\""
这使我无法设置和构建项目：
| => cd my-project; stack build
Error parsing targets: The specified targets matched no packages.
Perhaps you need to run 'stack init'?
我有Stack Version 1.5.1和GHC 8.0.2。可能是什么导致了这个？我真的很茫然。我没有在网上找到任何类似于我所描述的内容。