The problem:
chris@cubby ~ ❯❯❯ nix run -f '<nixpkgs>' zlib -c cabal install zlib
Resolving dependencies...
Configuring zlib-0.6.2...
Failed to install zlib-0.6.2
Build log ( /home/chris/.cabal/logs/ghc-8.2.2/zlib-0.6.2-L2Qec9Buml21zwTs2VzSGb.log ):
cabal: Entering directory '/tmp/cabal-tmp-31070/zlib-0.6.2'
Configuring zlib-0.6.2...
cabal: Missing dependency on a foreign library:
* Missing (or bad) header file: zlib.h
* Missing C library: z
This problem can usually be solved by installing the system package that
provides this library (you may need the "-dev" version). If the library is
already installed but in a non-standard location then you can use the flags
--extra-include-dirs= and --extra-lib-dirs= to specify where it is.
If the header file does exist, it may contain errors that are caught by the C
compiler at the preprocessing stage. In this case you can re-run configure
with the verbosity flag -v3 to see the error messages.
cabal: Leaving directory '/tmp/cabal-tmp-31070/zlib-0.6.2'
cabal: Error: some packages failed to install:
zlib-0.6.2-L2Qec9Buml21zwTs2VzSGb failed during the configure step. The
exception was:
ExitFailure 1
The requirement of zlib.h is declared here: https://github.com/haskell/zlib/blob/964a80a5451f4dd4244f9a86221fe2b4cb4bff2a/zlib.cabal#L74
The doc for the includes attibute https://www.haskell.org/cabal/users-guide/developing-packages.html#pkg-field-includes
A list of header files to be included in any compilations via C. This field applies to both header files that are already installed on the system and to those coming with the package to be installed. The former files should be found in absolute paths, while the latter files should be found in paths relative to the top of the source tree or relative to one of the directories listed in
include-dirs.
However, the Cabal documentation (this part, at least) neglects to mention what "absolute paths" the files are to be "found" in, so I am now stuck.
https://stackoverflow.com/questions/50479521/where-does-cabal-search-for-includes-files
pulling in
zlib.devandpkgconfigseems to fix the header issue. However, not the binary issue. The zlib build in Cabal does support pkgconfig. From mycabal.project.freeze:It's notable that most other libraries work, so something seems specific to zlib here.