git Libtool failures on hydra

[Ralf Wildenhues]

FWIW, just so that it's not forgotten,
<http://hydra.nixos.org/build/255158/log/raw>
shows these failures:

 34: shlibpath_overrides_runpath                     FAILED (shlibpath.at:68)
 35: Runpath in libtool library files                FAILED 
(runpath-in-lalib.at:61)
[...]
 66: lt_dlopen archive                               skipped (lt_dlopen_a.at:94)
 67: lt_dlopenext error messages                     FAILED 
(lt_dlopenext.at:196)
 68: ltdl API                                        skipped (ltdl-api.at:31)
 69: loadlibrary error messages                      skipped 
(loadlibrary.at:232)
[...]
 73: enforced lib prefix                             FAILED 
(need_lib_prefix.at:170)
[...]
101: Run tests with low max_cmd_len                  FAILED (cmdline_wrap.at:43)