I don't know if this is of any use in tracing down the problem, but I
have an "ltrace" of an attempted run below:
ishtar:usr/X11R6/lib/X11/fonts# ltrace -f -n 2 -S fc-cache TTF 2>&1
SYS_uname(0xbfffefa0) = 0
SYS_brk(NULL) = 0x0804b000
SYS_mmap(0xbfffecb0, 0x40019000, 0x40018ba0, 4096, 565) = 0x40019000
SYS_open("/etc/ld.so.preload", 0, 03) = -2
SYS_open("/etc/ld.so.cache", 0, 00) = 3
SYS_fstat64(3, 0xbfffe770, 0x40018ba0, 0x40018de0, 0) = 0
SYS_mmap(0xbfffe740, 0xbfffe770, 0x40018ba0, 3, 0x40018cb0) = 0x4001a000
SYS_close(3) = 0
SYS_open("/usr/lib/libfontconfig.so.1", 0, 00) = 3
SYS_read(3, "\177ELF\001\001\001", 512) = 512
SYS_fstat64(3, 0xbfffe820, 0x40018ba0, 0x40018de0, 0) = 0
SYS_mmap(0xbfffe710, 3, 0x40018ba0, 0xbfffe774, 0xbfffe744) = 0x40030000
SYS_mmap(0xbfffe710, 143672, 0x40018ba0, 0x40030000, 0xbfffe75c) = 0x40054000
SYS_mmap(0xbfffe710, 2280, 0x40018ba0, 0x40057000, 0xbfffe75c) = 0x40057000
SYS_close(3) = 0
SYS_open("/usr/X11R6/lib/libfreetype.so.6", 0, 027777764404) = 3
SYS_read(3, "\177ELF\001\001\001", 512) = 512
SYS_fstat64(3, 0xbfffe810, 0x40018ba0, 0x40018de0, 0) = 0
SYS_mmap(0xbfffe700, 3, 0x40018ba0, 0xbfffe764, 0xbfffe734) = 0x40058000
SYS_mmap(0xbfffe700, 230877, 0x40018ba0, 0x40058000, 0xbfffe74c) = 0x40091000
SYS_close(3) = 0
SYS_open("/usr/lib/libexpat.so.0", 0, 027777764364) = 3
SYS_read(3, "\177ELF\001\001\001", 512) = 512
SYS_fstat64(3, 0xbfffe800, 0x40018ba0, 0x40018de0, 0) = 0
SYS_mmap(0xbfffe6e0, 3, 0x40018ba0, 0xbfffe744, 0xbfffe714) = 0x40095000
SYS_mmap(0xbfffe6e0, 115536, 0x40018ba0, 0x40095000, 0xbfffe72c) = 0x400b2000
SYS_close(3) = 0
SYS_open("/lib/i686/libc.so.6", 0, 027777764344) = 3
SYS_read(3, "\177ELF\001\001\001", 512) = 512
SYS_fstat64(3, 0xbfffe7f0, 0x40018ba0, 0x40018de0, 0) = 0
SYS_mmap(0xbfffe690, 0x4001a000, 0x40018ba0, 4096, 574) = 0x400b5000
SYS_mmap(0xbfffe680, 3, 0x40018ba0, 0xbfffe6e4, 0xbfffe6b4) = 0x400b6000
SYS_mmap(0xbfffe680, 0x0012b730, 0x40018ba0, 0x400b6000, 0xbfffe6cc) = 0x401e2000
SYS_mmap(0xbfffe680, 7364, 0x40018ba0, 0x401e7000, 0xbfffe6cc) = 0x401e7000
SYS_close(3) = 0
SYS_munmap(0x4001a000, 87659) = 0
__libc_start_main(0x08049020, 2, 0xbffff224, 0x08049220, 0x08049280