Profiling with -Werror and GHC 8.2 is broken

[ndmitchell]

Using Windows 64bit, Stack 1.5, if I create a stack file for the Shake package pointing at nightly-2017-08-17 (a GHC 8.2 nightly), then run:

stack build --executable-profiling --library-profiling --ghc-options=-Werror

I get the error:

Configuring shake-0.15.11...

<no location info>: error:
Failing due to -Werror.

on the commandline: warning:
    -auto-all is deprecated: Use -fprof-auto instead

on the commandline: warning:
    -caf-all is deprecated: Use -fprof-cafs instead

The cause is

stack/src/Stack/Build/Source.hs

Line 160 in aa5003a

, if boptsLibProfile bopts || boptsExeProfile bopts

. I suggest either using the new flags (if you only care about newer GHC's), or doing a GHC version test.

I tested this with Shake, but I believe the problem applies to all packages.

[mgsloan]

Thanks for reporting! Looks like these have been old flags even when it was implemented. From the latest docs

-fprof-auto was known as -auto-all prior to GHC 7.4.1.

And indeed, the earliest supported ghc, 7.8 has -prof-cafs as well: https://downloads.haskell.org/~ghc/7.8.1/docs/html/users_guide/flag-reference.html

So, no version check is needed.

[ndmitchell]

Did you intend to close this issue?

[mgsloan]

Oh yeah forgot to mention i pushed a fix to master e21bfd9

[ndmitchell]

Thanks!