id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	os	architecture	failure	difficulty	testcase	blockedby	blocking	related
4818	[PATCH] OSX: undefined symbols; isysroot misconfiguration	altaic		"'''Machine:'''
{{{
Processor:     3.06 GHz Intel Core 2 Duo
Architecture:  x86/x86_64
OS:            Mac OS X 10.6.5
}}}

'''Bootstrap GHC Info:'''
{{{
$ghc --info
 [(""Project name"",""The Glorious Glasgow Haskell Compilation System"")
 ,(""Project version"",""7.0.0.20100924"")
 ,(""Booter version"",""6.12.3"")
 ,(""Stage"",""2"")
 ,(""Build platform"",""i386-apple-darwin"")
 ,(""Host platform"",""i386-apple-darwin"")
 ,(""Target platform"",""i386-apple-darwin"")
 ,(""Have interpreter"",""YES"")
 ,(""Object splitting"",""NO"")
 ,(""Have native code generator"",""YES"")
 ,(""Have llvm code generator"",""YES"")
 ,(""Use archives for ghci"",""True"")
 ,(""Support SMP"",""YES"")
 ,(""Unregisterised"",""NO"")
 ,(""Tables next to code"",""YES"")
 ,(""RTS ways"",""l debug  thr thr_debug thr_l thr_p  dyn debug_dyn thr_dyn thr_debug_dyn"")
 ,(""Leading underscore"",""YES"")
 ,(""Debug on"",""False"")
 ,(""LibDir"",""/Library/Frameworks/GHC.framework/Versions/700/usr/lib/ghc-7.0.0.20100924"")
 ,(""Global Package DB"",""/Library/Frameworks/GHC.framework/Versions/700/usr/lib/ghc-7.0.0.20100924/package.conf.d"")
 ]
}}}

'''Note:''' Other configure options cause the error; the following just happens to be the last one I used.

'''Configure Info:'''
{{{
$./configure --build=i386-apple-darwin --host=i386-apple-darwin --target=x86_64-apple-darwin

...

Configure completed successfully.

   Building GHC version  : 7.1.20101203

   Build platform        : i386-apple-darwin
   Host platform         : i386-apple-darwin
   Target platform       : x86_64-apple-darwin

   Bootstrapping using   : /usr/bin/ghc
      which is version   : 7.0.0.20100924

   Using GCC             : /usr/bin/gcc
      which is version   : 4.2.1

   ld       : /usr/bin/ld
   Happy    : /usr/local/bin/happy (1.18.5)
   Alex     : /usr/local/bin/alex (2.3.3)
   Python   : /usr/bin/python
   Perl     : /usr/bin/perl
   dblatex  : /usr/local/bin/dblatex
   xsltproc : /usr/bin/xsltproc
   HsColour : /Users/x/.cabal/bin/HsColour

   Building DocBook HTML documentation : YES
   Building DocBook PS documentation   : YES
   Building DocBook PDF documentation  : YES
}}}

'''Error:'''
{{{
""/usr/bin/ghc""    -H32m -O  -package-conf libraries/bootstrapping.conf   -i -iutils/unlit/. -iutils/unlit/dist/build -iutils/unlit/dist/build/autogen -Iutils/unlit/dist/build -Iutils/unlit/dist/build/autogen        -no-user-package-conf -rtsopts     -c utils/unlit/unlit.c -o utils/unlit/dist/build/unlit.o
""inplace/bin/mkdirhier"" utils/unlit/dist/build/tmp//.
""/usr/bin/gcc"" -o utils/unlit/dist/build/tmp/unlit  -march=i686 -m32 -isysroot /Developer/SDKs/MacOSX10.5.sdk -mmacosx-version-min=10.5 -fno-stack-protector              utils/unlit/dist/build/unlit.o    
Undefined symbols:
  ""_fopen$UNIX2003"", referenced from:
      _main in unlit.o
      _main in unlit.o
ld: symbol(s) not found
collect2: ld returned 1 exit status
make[1]: *** [utils/unlit/dist/build/tmp/unlit] Error 1
make: *** [all] Error 2
}}}

'''Hypothesis:''' GCC tries to use a hardcoded `-isysroot` from the following patch to compile `unlit`, which cannot be mixed with other components which seem to be using the default SDK on my machine. Even when I specify `--with-macosx-deployment-target=10.5` for configure, unlit still fails. I'm thinking that the deployment target only affects stage 2 or something, so earlier stages are using a combination of the default SDK (in my case, 10.6) and the hardcoded one (10.5). Here's the patch that caused the problem:
{{{
[Tell gcc to support back to OS X 10.5
Ian Lynagh <igloo@earth.li>**20101203201558
 Ignore-this: f02d70e5b9cce50137981c6cb2b62a18
] hunk ./aclocal.m4 27
+    case $$1 in
+    i386-apple-darwin|x86_64-apple-darwin)
+        # We support back to OS X 10.5
+        $2=""$$2 -isysroot /Developer/SDKs/MacOSX10.5.sdk -mmacosx-version-min=10.5""
+        $3=""$$3 -isysroot /Developer/SDKs/MacOSX10.5.sdk -mmacosx-version-min=10.5""
+        ;;
+    esac
+
}}}

'''Temporary Workaround:''' Revert above patch and apply the following:
{{{
--- old-ghc/aclocal.m4	2010-12-05 14:29:54.000000000 -0500
+++ new-ghc/aclocal.m4	2010-12-05 14:29:54.000000000 -0500
@@ -24,6 +24,14 @@
         ;;
     esac
 
+    case $$1 in
+    i386-apple-darwin|x86_64-apple-darwin)
+        # Only support OS X 10.5 and later
+        $2=""$$2 -mmacosx-version-min=10.5""
+        $3=""$$3 -mmacosx-version-min=10.5""
+        ;;
+    esac
+
     # If gcc knows about the stack protector, turn it off.
     # Otherwise the stack-smash handler gets triggered.
     echo 'int main(void) {return 0;}' > conftest.c
}}}

'''Permanent Resolution:''' Instead of hardcoding `-isysroot` in aclocal.m4 (`-mmacosx-version-min` is fine to hard-code, though), we should have build, host, and target isysroots (or stage0, stage1, etc. isysroots), which are detected/specified by the configure script. It's possible that separate isysroots aren't necessary, however in any case, all the components in a stage must use the same isysroot if they're to be linked together.
"	bug	closed	normal		Build System	7.1	fixed		william.knop.nospam@…	MacOS X	Unknown/Multiple	Building GHC failed