Recent changes introduce bsd-getline.c compatibility, but the build fails for me when configured without any options:

gcc -g -O2 -pipe -Wall -Wpointer-arith -Wuninitialized -Wsign-compare -Wformat-security -Wsizeof-pointer-memaccess -Wno-pointer-sign -Wno-unused-result -fno-strict-aliasing -mfunction-return=thunk -mindirect-branch=thunk -D_FORTIFY_SOURCE=2 -ftrapv -fno-builtin-memset -fstack-protector-strong -fPIE   -I. -I.. -I. -I./..  -D_XOPEN_SOURCE=600 -D_BSD_SOURCE -D_DEFAULT_SOURCE -DHAVE_CONFIG_H -c bsd-getline.c
bsd-getline.c:50:1: error: static declaration of ‘getdelim’ follows non-static declaration
 getdelim(char **buf, size_t *bufsiz, int delimiter, FILE *fp)
 ^~~~~~~~
In file included from /usr/include/resolv.h:58,
                 from ../openbsd-compat/getrrsetbyname.h:59,
                 from ../openbsd-compat/openbsd-compat.h:44,
                 from ../includes.h:175,
                 from bsd-getline.c:36:
/usr/include/stdio.h:606:20: note: previous declaration of ‘getdelim’ was here
 extern _IO_ssize_t getdelim (char **__restrict __lineptr,
                    ^~~~~~~~
make[1]: *** [Makefile:98: bsd-getline.o] Error 1

This function is just internal and therefore it should be defined with some compat prefix to not conflict with system functions, or it should not be built if the system one can be used.

Reproducer:
 * configure && make master on current Fedora 28.

Following patch allows me to build the current master:

diff --git a/openbsd-compat/bsd-getline.c b/openbsd-compat/bsd-getline.c
index 681062e8..1424c39e 100644
--- a/openbsd-compat/bsd-getline.c
+++ b/openbsd-compat/bsd-getline.c
@@ -47,7 +47,7 @@
 #include <string.h>
 
 static ssize_t
-getdelim(char **buf, size_t *bufsiz, int delimiter, FILE *fp)
+xxx_getdelim(char **buf, size_t *bufsiz, int delimiter, FILE *fp)
 {
 	char *ptr, *eptr;
 
@@ -92,7 +92,7 @@ getdelim(char **buf, size_t *bufsiz, int delimiter, FILE *fp)
 ssize_t
 getline(char **buf, size_t *bufsiz, FILE *fp)
 {
-	return getdelim(buf, bufsiz, '\n', fp);
+	return xxx_getdelim(buf, bufsiz, '\n', fp);
 }
 
 #endif