In a freshly cloned GHC code base (c6462ab0...), in my system,`make test TEST="T13780c T13822"` fails. That is while `./validate` passes. I am rather new to GHC code base, and not so familiar with its build and testing system. So I was wondering whether this is an intended behaviour (e.g., some test cases are intentionally left out of `./validate`). Specifically, I follow the following steps: (1) `git clone --recursive git://git.haskell.org/ghc.git` (2) `cd ghc` (3) `cp mk/build.mk.sample mk/build.mk` (4) set `BuildFlavour = devel2` and then (5) ./boot (6) ./configure (7) make -j4 (8) make test TEST="T13780c T13822" I build in a variant of the docker image for GHC development on Linux (64 bit), if it matters. As it seems, Alan also gets the similar result on his system. I am investigating this, since my development of Growable ASTs is stalled due to some "GHC panic bug" when validating. (In my repo[1], I can successfully build with steps (2)-(7) above but `./validate` (and `make test TEST="T13780c T13822"`) fails) Thanks, Shayan [1] https://github.com/shayan-najd/GrowableGHC