[GHC] #3841: build for libffi assumes tar supports -z

[GHC]

#3841: build for libffi assumes tar supports -z
---------------------------------+------------------------------------------
    Reporter:  duncan            |       Owner:                     
        Type:  bug               |      Status:  new                
    Priority:  normal            |   Component:  Build System       
     Version:  6.12.1            |    Keywords:                     
          Os:  Solaris           |    Testcase:                     
Architecture:  Unknown/Multiple  |     Failure:  Building GHC failed
---------------------------------+------------------------------------------
 {{{
 cd libffi && /usr/bin/tar -zxf ../ghc-tarballs/libffi/libffi*.tar.gz
 tar: z: unknown function modifier
 Usage: tar {c|r|t|u|x}[BDeEFhilmnopPqTvw@[0-7]][bfk][X...] [blocksize]
 [tarfile] [size] [exclude-file...] {file | -I include-file | -C directory
 file}...
 gmake[1]: *** [libffi/stamp.ffi.configure] Error 1
 }}}

 The libffi/ghc.mk uses
 {{{
 cd libffi && $(TAR) -zxf ../ghc-tarballs/libffi/libffi*.tar.gz
 }}}
 A quick grep indicates this is the only instance that assumes the -z flag.
 Other instances in the ghc build system that use tar do the compression
 separately, eg in ghc.mk:
 {{{
 "$(TAR)" chf - $(SRC_DIST_NAME) 2>$src_log | bzip2
 >$(TOP)/$(SRC_DIST_TARBALL)
 }}}

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/3841>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler