Hadrian: suppress Shake debug output

When I run a test (e.g. with build test --only="SomeTest"), the output I get contains one of two suffixes:

1. Upon success, I get stuff like

shakeArgsWith                        0.000s    0%                           
Function shake                       0.010s    0%                           
Database read                        0.323s   12%  ===                      
With database                        0.031s    1%                           
Running rules                        2.301s   86%  =========================
Pool finished (1786 threads, 5 max)  0.003s    0%                           
Cleanup                              0.000s    0%                           
Total                                2.669s  100%                           
Build completed in 2.67s

2. Upon failure, I get stuff like

Error when running Shake build system:
  at want, called at src/Main.hs:104:30 in main:Main
* Depends on: test
* Raised the exception:
user error (tests failed)


hadrian-util: Received ExitFailure 1 when running
Raw command: /Users/rae/ghc/ghc/hadrian/build-cabal --build-root=_build --flavour=default -j5 --flavour=devel2+werror test --only=KindEqualities2 --freeze1 --freeze2
Run from: /Users/rae/ghc/ghc

Neither of these suffixes are useful for Hadrian users (as opposed to Hadrian developers), and they separate me from the information I want, about the tests passing or failing.

Is there a way to suppress?