Stupid question about Cabal file
Hi, Excuse me in advance if this is a trivial question, but I have been unable to find (understand?) the answer in Cabal's documentation. My issue is simple : I build a Cabal package named, let's say, "foo". That package is a library (libHSfoo.a, something like that), which exposes its Foo.Bar and Foobar modules. I wrote the cabal file, register it, everything seems fine. The issue comes when I try to use that package when compiling a main program, like this : ghc -package foo MyMain.hs [other options] I get an error about the compiler not finding the interface files Foobar.hi and Bar.hi, as I have "import Bar" and "import Foo.Bar" in my "MyMain.hs" file. Of course, I could add "-l" flags to point to the ".hi" files that I used to compile my package, but I get the well-known issue about the fact that the package's names of the interface files (which were compiled with the "-package-name foo" option) are not the correct ones ("Bad interface file: ../foo/Foobar.hi, Something is amiss; requested module main:Foobar differs from name found in the interface file foo:Foobar") ; and that solution is ugly anyway. So far, I found some Cabal documentation talking about the import-dirs property, but I did not manage to "make it work", I mean, my package does not seems to "include" the interface files. I am sure, on the other hand, that it is possible :) Sincerely yours, Fernand
Am Donnerstag, 26. Juni 2008 14:01 schrieb Fernand:
Hi,
Excuse me in advance if this is a trivial question, but I have been unable to find (understand?) the answer in Cabal's documentation. My issue is simple : I build a Cabal package named, let's say, "foo". That package is a library (libHSfoo.a, something like that), which exposes its Foo.Bar and Foobar modules. I wrote the cabal file, register it, everything seems fine. The issue comes when I try to use that package when compiling a main program, like this :
ghc -package foo MyMain.hs [other options]
I get an error about the compiler not finding the interface files Foobar.hi and Bar.hi, as I have "import Bar" and "import Foo.Bar" in my "MyMain.hs" file. Of course, I could add "-l" flags to point to the ".hi" files that I used to compile my package, but I get the well-known issue about the fact that the package's names of the interface files (which were compiled with the "-package-name foo" option) are not the correct ones ("Bad interface file: ../foo/Foobar.hi, Something is amiss; requested module main:Foobar differs from name found in the interface file foo:Foobar") ; and that solution is ugly anyway.
So far, I found some Cabal documentation talking about the import-dirs property, but I did not manage to "make it work", I mean, my package does not seems to "include" the interface files. I am sure, on the other hand, that it is possible :)
Sincerely yours,
Fernand
Did you create your package using Cabal, i.e. have a module Setup.(l)hs in the same directory as the .cabal file and then runhaskell Setup.hs configure --prefix=WhereYouWantIt runhaskell Setup.hs build runhaskell Setup.hs haddock (optionally) runhaskell Setup.hs install ? Then you shouldn't even need the -package option to use it, ghc-pkg would know where to find the interface files. Cheers, Daniel
Daniel Fischer пишет:
Did you create your package using Cabal, i.e. have a module Setup.(l)hs in the same directory as the .cabal file and then
runhaskell Setup.hs configure --prefix=WhereYouWantIt runhaskell Setup.hs build runhaskell Setup.hs haddock (optionally) runhaskell Setup.hs install ?
Then you shouldn't even need the -package option to use it, ghc-pkg would know where to find the interface files.
Cheers, Daniel
No, I did not, because I actually inherited a large Makefile with huge dependencies and twisted built options. If using Setup is the right (and only) way to create the package, I will then try it. thank you, Fernand
Am Donnerstag, 26. Juni 2008 14:56 schrieb Fernand:
Daniel Fischer пишет:
Did you create your package using Cabal, i.e. have a module Setup.(l)hs in the same directory as the .cabal file and then
runhaskell Setup.hs configure --prefix=WhereYouWantIt runhaskell Setup.hs build runhaskell Setup.hs haddock (optionally) runhaskell Setup.hs install ?
Then you shouldn't even need the -package option to use it, ghc-pkg would know where to find the interface files.
Cheers, Daniel
No, I did not, because I actually inherited a large Makefile with huge dependencies and twisted built options. If using Setup is the right (and only) way to create the package, I will then try it.
thank you,
Fernand
If it's a complicated build, you should certainly take a close look at the Cabal user guide, because then you will probably need more than main = defaultMain in your Setup.hs. On the other hand, the GHC user's guide should also contain some sections on building and registering packages. The Cabal / Setup way is intended to be the simplest and standard way to build packages, but it's not the only one and won't be for a long time. Cheers, Daniel
I had a look at the Distribution.Make import, which may be the answer. Thank you for pointing the GHC documentation : I found a way to have the build process work, but after having patched my local package.conf file by hand, and installed manually the interfaces files accordingly. I now just need to understand how to obtain the same result using make, I think. Haskelly yours, Fernand Daniel Fischer пишет:
If it's a complicated build, you should certainly take a close look at the Cabal user guide, because then you will probably need more than main = defaultMain in your Setup.hs. On the other hand, the GHC user's guide should also contain some sections on building and registering packages.
The Cabal / Setup way is intended to be the simplest and standard way to build packages, but it's not the only one and won't be for a long time.
Cheers, Daniel
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Fernand