http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49992
--- Comment #10 from Jack Howarth <howarth at nitro dot med.uc.edu> 2011-08-08 19:27:58 UTC --- This is radar://6320843 "duplicate symbols from static libraries not properly ignored" revisiting us... 26-Oct-2008 10:43 AM Jack Howarth: Xcode 3.2 fails to link cc1plus-dummy from gcc 4.3.2 due to a reappearance of radar 5808800//5779681 which was appeared and was fixed during the Xcode 3.1 development cycle. The bug causes the following link failure while building FSF gcc 4.3.2... etc. Their response was... 06-Nov-2008 03:04 PM KIT CHEUNG : Engineering has requested the following information in order to further investigate this issue: How was libbackend.a created? Its table of contents is wrong because it contains entries for tentative definitions. We ran ranlib on libbackend.a then bad_link_command succeeded. If you run: ranlib -c libbackend.a then bad_link_command fails again. So my guess is that the build used the -c option when creating libbackend.a. Is there a reason for this? Darwin static archives traditionally do not have common symbols in there table of contents. The -c option forces common symbols into the table of contents and causes this problem.