Do not use pkg-config to locate zlib on FreeBSD

[arrowd]

FreeBSD has zlib in its base system, so it is guaranteed to be present. At the same time it doesn't provide a .pc file, so Cabal fails to fullfill the pkgconfig-depends: zlib dependency.

[TeofilC]

Thanks @arrowd !

[arrowd]

May I also ask you to make a new Hackage release ASAP?
Right now, when packaging any Haskell application that transitively uses digest for FreeBSD, it fails due to not finding zlib.

[TeofilC]

Sure, no worries. Here's the release: https://hackage.haskell.org/package/digest-0.0.1.7

[arrowd]

Fantastic, thanks for the quick resolution!

[rybak]

Disclaimer: I'm not very familiar with Stack and Cabal, I'm just trying to compile a Haskell project.

Is it possible that the same problem described above for FreeBSD is present on Ubuntu?

I was trying to build master branch of a project using stack and I got:

$ stack build
[...]
digest                       > configure                                                                  
digest                       > Configuring digest-0.0.1.4...                                              
digest                       > Cabal-simple_SvXsv1f__3.6.3.0_ghc-9.2.5: The pkg-config package 'zlib' is  
digest                       > required but it could not be found.                                        
digest                       >                                                                            
[...]
Error: [S-7282]
       Stack failed to execute the build plan.
       
       While executing the build plan, Stack encountered the following errors:
       
       [S-7011]
       While building package digest-0.0.1.4 (scroll up to its section to see the error) using:

After checking and finding that digest has a newer version, I've upgraded from resolver: lts-20.8 to resolver: lts-20.17, but I got the same error with digest-0.0.1.7:

digest                           > configure                                                           
digest                           > Configuring digest-0.0.1.7...                                     
digest                           > Cabal-simple_SvXsv1f__3.6.3.0_ghc-9.2.7: The pkg-config package 'zlib' is
digest                           > required but it could not be found.           
digest                           >                                               
[...]
Error: [S-7282]
       Stack failed to execute the build plan.
       
       While executing the build plan, Stack encountered the following errors:
       
       [S-7011]
       While building package digest-0.0.1.7 (scroll up to its section to see the error) using:

So I went to an older commit of the project I'm trying to compile, which uses resolver: lts-20.4, which seems to pick up digest-0.0.1.3, and the build failure went away. According to CHANGELOG.md, version 0.0.1.4 was the one that changed the way zlib was found.

[TeofilC]

It should work fine on Ubuntu. Make sure you have pkg-config and the zlib development packages installed.
On my ubuntu machine I can run the following command with no problem:

 pkg-config zlib --version

[rybak]

Make sure you have pkg-config and the zlib development packages installed.

Searching for the error message turned up this similar sounding issue, so making sure that I have the -dev package of zlib was actually the first thing I did. As it turns out, Ubuntu package haskell-platform actually depends on zlib1g-dev.

Another story for pkg-config , however. To my shame, trying to build this project is the first time I learned about existence of pkg-config. Indeed, after a sudo apt install pkg-config the build is successful. Thank you very much! :-D

Why didn't Stack complain about pkg-config not being installed? From my inexperienced reading of the build log it seems as though it was an error reported by pkg-config. It seems that Stack can complain about missing pkg-config.

Even better, why doesn't Stack install a snapshot of pkg-config on its own like it does with GHC? I thought that Stack was all about snapshots and sandboxing and such.

I guess both of those are questions to developers of Stack, though. Or maybe developers of Nix, I can't tell :-/

P.S. After some poking at apt it seems that I had the 32 bit version of pkg-config installed, so that might have been the root cause.