当谷歌搜索此错误时没有看到任何相关结果，所以我想将其发布。
stack build
Building all executables for `gitchapter' once. After a successful build of all of them, only specified executables will be rebuilt.
gitchapter-0.1.0.0: build (exe)
Preprocessing executable 'app' for gitchapter-0.1.0.0..
Building executable 'app' for gitchapter-0.1.0.0..
Preprocessing executable 'test' for gitchapter-0.1.0.0..
Warning: Enabling workaround for Main module 'Main' listed in 'other-modules'
Building executable 'test' for gitchapter-0.1.0.0..
illegaly!
<no location info>: error:
output was redirected with -o, but no output will be generated
because there is no Main module.
-- While …