Alp You've written a helpful wiki page describing how to use Hadrian https://gitlab.haskell.org/ghc/ghc/blob/master/hadrian/doc/make.md Could you document where build-products live? I often look at .hi files. Could you add * How to do the equivalent of "sh validate" * When validating, how to do things like this: GhcStage1HcOpts += -DDEBUG -O GhcStage2HcOpts += -Wwarn -ticky GhcLibHcOpts += -ticky -Wwarn BUILD_PROF_LIBS = NO SplitObjs = YES HADDOCK_DOCS = NO BUILD_SPHINX_HTML = NO BUILD_SPHINX_PDF = NO * After modifying the source code, how to make stage1 compiler (only). In 'make' it is $ cd compiler; make 1 * After modifying the source code, build the stage2 compiler (only). In 'make' it is $ cd compiler; make 2 Perhaps you say build -freeze1? * In the testsuite, how to use the stage1 compiler $ make stage=1 TEST=T2543 * In nofib, how to build one benchmark, with extra flags, perhaps even with the stage1 compiler $ make stage=1 EXTRA_HC_OPTS="-ticky -ddump-simpl -ddump-stg" Thanks! Simon