Regression: GHC doesn't show filepaths by default anymore

Sorry for chiming in so late, I didn't notice #12807 (closed) and I didn't build GHC HEAD for several days, otherwise I would have cried out loud sooner.

I'm deliberately declaring this a regression since I consider this a bad default. And not for the mere fact that change is bad ;-)

Don't get me wrong, I can see usefulness in the -fno-show-source-paths feature (although I consider it inconsistent, see below), but it's a bad default because in my workflows I rely on seeing the source-path by default, and I see no way to restore this as the default behaviour of GHC short of patching GHC.

 [1 of 1] Compiling Control.Concurrent.STMSupply (.hs -> .o)

First of all, if we drop filepaths, then please drop them completely, either I need more information about which .hs file was used as source, or I don't need it at all, so this (.hs -> .o) suffix is just noise to me; not the least because the -> .o part carries almost no information for me. If the premise of -fno-show-source-paths is that we know how we called GHC and thereby know what is being compiled, showing (.hs -> .o) is pointless.

Morever, -f(no-)show-source-paths is a lie/misnomer, as it doesn't only control the *source* path display, but *also* the *output* path display!

Also, when invoking GHC, and pass it multiple include folders, sometimes GHC picks up the wrong module (or rather one I didn't intend), having it print the source file path by default has been a big timesaver to me, detecting when I was barking up the wrong source-file while figuring out why stuff didn't work.

Finally, this also breaks my shell-based workflow because I'm used to copy'n'paste filepaths from GHC's output, especially for longer source-paths where tab-completing my way to the source path is too tedious.

This is just the first impression I got while being exposed to this UI change today, there may be other regressions I'd notice when having to use this for longer.

So, in summary I propose to

• Make -fshow-source-paths the default again

• drop the (.hs->.o) suffix in -fno-show-show-source-paths

• consider a better name; actually, I can see cases where you want to omit only the output-path display (since it's imho often less interesting to know the output files names; even though sometimes you may want to know it since it can be affected in a non-obvious way by output-dir flags), e.g. maybe

• Have -f(no-)show-source-paths control the source-path display

• Have -f(no-)show-output-paths control the output-path display

• As a compromise, consider -fshow-source-paths -fno-show-output-paths becoming the new default.

Trac metadata

Trac field	Value
Version	8.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	low
Resolution	Unresolved
Component	Compiler
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