`pprTrace*` should be in GHC.Prelude
A recent change moved pprTrace*
to its own module GHC.Driver.Ppr
. A common pattern in GHC is to comment out (rather than delete) pprTrace
calls useful for printf-debugging information so one can re-use them at a later time.
That pattern now has become very cumbersome, because modules rarely have live calls to pprTrace
and hence the module import for GHC.Driver.Ppr
is redundant, so no code passing the validate flavour will have these imports and I have to add them everytime I need them. When I'm done debugging, I usually comment out the pprTrace
calls again. But now I also have to remove the import again, because otherwise it won't pass validate.
Hence it should be available from GHC.Prelude
or some other prominent module, like it used to be.