libtool: Stripped link flags

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1 13.1 Why does libtool strip link flags when creating a library?
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1 When creating a shared library, but not when compiling or creating a
1 program, 'libtool' drops some flags from the command line provided by
1 the user.  This is done because flags unknown to 'libtool' may interfere
1 with library creation or require additional support from 'libtool', and
1 because omitting flags is usually the conservative choice for a
1 successful build.
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1    If you encounter flags that you think are useful to pass, as a
1 work-around you can prepend flags with '-Wc,' or '-Xcompiler ' to allow
1 them to be passed through to the compiler driver (⇒Link mode).
1 Another possibility is to add flags already to the compiler command at
1 'configure' run time:
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1      ./configure CC='gcc -m64'
1 
1    If you think 'libtool' should let some flag through by default,
1 here's how you can test such an inclusion: grab the Libtool development
1 tree, edit the 'ltmain.in' file in the 'libltdl/config' subdirectory to
1 pass through the flag (search for 'Flags to be passed through'),
1 re-bootstrap and build with the flags in question added to 'LDFLAGS',
1 'CFLAGS', 'CXXFLAGS', etc.  on the 'configure' command line as
1 appropriate.  Run the testsuite as described in the 'README' file and
1 report results to the Libtool bug reporting address
1 <bug-libtool@gnu.org>.
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