lilypond-2.18.2 touches fontconfig database during build

[Yuri]

The FreeBSD port build fails because framework (poudriere) detects that 
the file 
/var/db/fontconfig/eaa7e6b04ed2319438e190edebf0c841-le64.cache-7 is touched.


Here is the stack:

  3  70132                     rename:entry 
file1=/var/db/fontconfig//eaa7e6b04ed2319438e190edebf0c841-le64.cache-7.NEW 
file2=/var/db/fontconfig//eaa7e6b04ed2319438e190edebf0c841-le64.cache-7 
pid=5953 exe=lilypond
              libc.so.7`_rename+0xa
              libfontconfig.so.1.9.2`0x80231a443
              libfontconfig.so.1.9.2`0x802324687
              libfontconfig.so.1.9.2`0x80231c100
              libfontconfig.so.1.9.2`FcConfigAppFontAddDir+0xaa
              lilypond`init_fontconfig(void)+0x224
              lilypond`main_with_guile(void*, int, char**)+0x257
              libguile.so.17.4.0`0x800be0d74
              libguile.so.17.4.0`0x800bb194f
              libguile.so.17.4.0`scm_c_catch+0x1f7
libguile.so.17.4.0`scm_c_with_continuation_barrier+0x94
              libguile.so.17.4.0`scm_with_guile+0x2d
              libguile.so.17.4.0`scm_boot_guile+0x27
              lilypond`main+0x113a
              lilypond`_start+0x17f
              ld-elf.so.1`allocate_initial_tls+0x10

The operation was to build lilypond, and to install it into the stage 
directory. It shouldn't touch anything outside the stage directory.


Yuri