Cabal: Specifying remote Git repositories without .cabal file?

[pythonissam]

Suppose we want use a remote git repository and write so:

source-repository-package
  type: git
  location: https://github.com/wataru86/han2zen
  tag: 7b13cb39506453b07eb38d5ad24799926f641bde

However, when that repository doesn't contain a cabal file, cabal complains with NoCabalFileFound. Of course we can generate cabal files and include it into git, but if there're alternatives, we'd like to know. Thanks.

[phadej]

Hmm, this is nasty. Would it be enough if one would be able to specify a command(s) to be run (which would prepare the working directory to sdisted).

I'm :-1: of teaching cabal about hpack or anything else specifically. In fact there are

• autoreconf -i
• hpack
• dhall-to-cabal
• make (e.g. in alex, almost)

and probably more. Requiring a user to specify the preprocessors (field name up to bikeshedding) is IMHO more future-proof way:

  type: git
  location: https://github.com/wataru86/han2zen
  tag: 7b13cb39506453b07eb38d5ad24799926f641bde
  preprocessors:  hpack

would then work.

Things to look up in the implementation:

• Windows: restricting to a single parametrless commands (i.e. no shell etc.) would do the job?
• interaction with subdirectories (preprocess before or after chdir, should one be able to specify?)
• how preprocessing would interact with sharing of checkouts (do we even share them?)