On 10/11/2014 9:24 PM, Herbert Valerio Riedel wrote:
Consider the following trivial program:
module Main where
foreign import ccall unsafe "time.h tzset" c_tzset :: IO ()
main :: IO() main = c_tzset
[...]
However, when loaded into GHCi, the RTS linker fails to find `tzset`:
$ ghci tz.hs
[...]
ByteCodeLink: can't find label During interactive linking, GHCi couldn't find the following symbol: tzset
Strange, I tried it under HaskellPlatform-2014.2, it works, I didn't see the failure. And I tried it in both Windows cmd and msys2 shell.
However, when I prefix a `_` to the symbol-name in the FFI import, i.e.
foreign import ccall unsafe "time.h tzset" c_tzset :: IO ()
I guess it should read: foreign import ccall unsafe "time.h _tzset" c_tzset :: IO () It works too. Actually both _tzset and tzset exist in include/time.h, only tzset is old style name. They will be linked as the same function __imp__tzset. -- cg