Trying to add a target with libexec_LIBRARIES results in an error: error: 'libexecdir' is not a legitimate directory for 'LIBRARIES'
But it looks like having libraries in libexec is something already in use by a few things. On a Fedora 20 machine: $ find /libexec -name \*.so /usr/libexec/p7zip/7z.so /usr/libexec/coreutils/libstdbuf.so /usr/libexec/sudo/sudo_noexec.so /usr/libexec/sudo/sudoers.so /usr/libexec/sudo/group_file.so /usr/libexec/sudo/system_group.so /usr/libexec/systemtap/libHelperSDT_amd64.so /usr/libexec/gcc/x86_64-redhat-linux/4.8.3/liblto_plugin.so /usr/libexec/deja-dup/tools/libduplicity.so Shouldn't automake support installing libraries in libexec?
