On Thu, Dec 29, 2011 at 2:45 PM, Antoine Latter
[...]
When GHC opens files for reading, it asks windows to disallow write access to the file. I'm guessing that Framemaker has the file open for writing, so GHC can't get that permission.
In fact, this is required behavior according to the Haskell Report:
Implementations should enforce as far as possible, at least locally to the Haskell process, multiple-reader single-writer locking on files. That is, there may either be many handles on the same file which manage input, or just one handle on the file which manages output.
I guess on Windows, "as far as possible" means locking it across the whole system. (See http://www.haskell.org/onlinereport/haskell2010/haskellch41.html#x49-3280004... for the gory details) -- Chris