[Haskell-cafe] Trying desperately to make a c library binding on Windows

[Nicu Ionita]

What I don't understand is why the stack message sounds:

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.

Why would be an include directory necessary, if I only miss the library? 
I understand that the includes are needed to compile the (generated) C 
sources, but why needed to link? Or is maybe just a typo in the stack 
message?

Nicu

Am 17.03.2016 um 23:50 schrieb Nicu Ionita:
> Am 17.03.2016 um 23:24 schrieb Theodore Lief Gannon:
>> > I am on Win 7, using stack (configured for lts-4.2) under MinGW.
>>
>> Stack itself provides MSYS2/MinGW during builds on Windows. Do you 
>> mean you have an independent MinGW shell that you're opening, and 
>> then running stack from there?
>
> Yes, I work under the git bash (git for Windows comes with an own msys).
>
>> If so, assuming you're not already using this flag, try:
>>
>> stack build --skip-msys
>
> Just tried that now, same result.
>>
>> This tells stack that it's already running inside a unix-style shell, 
>> and shouldn't assert its related path overrides.
>>
>> Beyond that, it would help to have more information about exactly 
>> where everything is and how it's being built/invoked/etc.
>
> Project is under:
> J:\Projects\BaseOh
>
> Library is under:
> J:\BO\lib
>
> and is called:  libbayesopt.a
>
> (under bash they are called /j/Projects/BaseOh and /j/BO/lib, needless 
> to say I tried those too, but they are not found, as the programs know 
> only Windows style paths).
>
> So beeing under the git bash in the project directory, I type:
> > stack build
>
> or even:
> > stack build --extra-lib-dirs=j:\\BO\\lib
>
> But in both cases, if the line "extra-libraries: bayesopt" is present 
> in the cabal file, then configure does not work (message below).
>
> Inbetween I upgraded stack (now is version 1.0.4.2 x86_64). When I try 
> to build, I get the message:
>
> Continuing despite missing tool: msys2
>
> after which the build continues and brings exactly the same failures.
>
>>
>> On Thu, Mar 17, 2016 at 2:19 PM, Nicu Ionita <nicu.ionita at acons.at 
>> <mailto:nicu.ionita at acons.at>> wrote:
>>
>>     Hi all,
>>
>>     I am really stuck with my try to make a Haskell binding for the
>>     library bayesopt on Windows.
>>     In theory it looks all simple, just put some lines in the cabal
>>     configuration file:
>>
>>     ...
>>     extra-lib-dirs:      /path/to/the/lib    -- contains the file
>>     libbayesopt.a
>>     extra-libraries:    bayesopt
>>     ...
>>
>>     But whatever I tried, I can't step over the configuration phase,
>>     coz I get (I'm compiling with stack):
>>
>>     Configuring BaseOh-0.1.0.0...
>>     setup-Simple-Cabal-1.22.5.0-x86_64-windows-ghc-7.10.3.exe: Missing
>>     dependency
>>     on a foreign library:
>>     * Missing C library: /j/BO/lib/libbayesopt.a
>>     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 I comment those lines out, then the configure phase succeeds,
>>     the library is compiled (i.e. my binding library), but a test
>>     executable in the same project does of course not compile, as
>>     symbols are missing:
>>
>>     ...
>>     In-place registering BaseOh-0.1.0.0...
>>     Preprocessing executable 'test' for BaseOh-0.1.0.0...
>>     [1 of 2] Compiling Optimisation.Stochastic.BayesOpt (
>>     src\Optimisation\Stochasti
>>     c\BayesOpt.hs,
>> .stack-work\dist\x86_64-windows\Cabal-1.22.5.0\build\test\test-tm
>>     p\Optimisation\Stochastic\BayesOpt.o )
>>     ghc.exe: unable to load package `BaseOh-0.1.0.0'
>>     ghc.exe:
>> J:\Projects\BaseOh\.stack-work\dist\x86_64-windows\Cabal-1.22.5.0\build
>>     \HSBaseOh-0.1.0.0-GdNObdePATgDIW1I2OVwEc.o: unknown symbol
>>     `initialize_parameter
>>     s_to_default'
>>
>>     --  While building package BaseOh-0.1.0.0 using:
>>     ...
>>
>>     Does somebody have some idea, what is going on?
>>
>>     I am on Win 7, using stack (configured for lts-4.2) under MinGW.
>>     (I'm using inline-c to make the bindings, and the same trick for
>>     include - include-dirs: ... - worked fine.)
>>
>>     Thanks, and sorry for the longer email.
>>     Nicu
>>     _______________________________________________
>>     Haskell-Cafe mailing list
>>     Haskell-Cafe at haskell.org <mailto:Haskell-Cafe at haskell.org>
>> http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe
>>
>>
>
> _______________________________________________
> Haskell-Cafe mailing list
> Haskell-Cafe at haskell.org
> http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe