我自己一小时前才碰到的！
new-test尚不支持--show-details标志：https://github.com/haskell/cabal/issues/4766
bug报告中的讨论表明，也许--show-details无论如何都是一个错误的特性，它应该总是流。

从PR 5455开始（Cabal-install 3之后可用，请参阅变更记录），您可以使用旗标：
--**test-**show-details=streaming
示例：

~/hackage-server $ cabal test --enable-tests --test-show-details=streaming ReverseDependenciesTest
Building test suite 'ReverseDependenciesTest' for hackage-server-0.5.1..
Test suite ReverseDependenciesTest: RUNNING...
ReverseDependenciesTest
  with set [beeline->mtl] and querying for mtl, we get beeline:                                        OK
  revPackageName selects only latest version, even if it has no dependency on chosen package:          OK
  revPackageId does select old version when queried with old reverse dependency:                       OK
  revPackageName can find multiple packages:                                                           OK
  with set [beeline->mtl->base, lens->mtl->base], revPackageFlat 'base' finds [beeline, lens, mtl]:    OK
  with set [beeline->mtl->base, lens->mtl->base], revPackageStats 'base' return 1,3:                   OK
  with set [beeline->mtl->base, lens->mtl->base], queryReverseDeps 'base' return [mtl],[beeline,lens]: OK

All 7 tests passed (0.01s)