3.6 and 3.7 CFEngine compilation on old FreeBSD

Hello, I have got an issue.
When I'm trying to compile CFEngine 3.6 or 3.7 from sources on my old FreeBSD 7.1 i386, I have got an error in compileing libcompat in getline.c file:

SED libpromises/enterprise_extension.c
SED libpromises/enterprise_extension.h
Making all in libcompat
CC generic_at.lo
generic_at.c: In function 'generic_at_function':
generic_at.c:72: warning: 'fchdir_ret' may be used uninitialized in this function
CC getopt.lo
CC getopt1.lo
CC strnlen.lo
CC strndup.lo
CC memdup.lo
CC getline.lo
getline.c:44: error: expected '=', ',', ';', 'asm' or '_attribute_' before 'getline'
getline.c:54: error: expected '=', ',', ';', 'asm' or '_attribute_' before 'getdelim'
getline.c:128: error: expected '=', ',', ';', 'asm' or '_attribute_' before 'getline'
gmake[2]: *** [getline.lo] Error 1
gmake[1]: *** [all-recursive] Error 1
gmake: *** [all] Error 2

What's root cause of this problem and how can it may be fixed ?