configure options:

+ ./configure --build=x86_64-redhat-linux-gnu --host=x86_64-redhat-linux-gnu --program-prefix= --disable-dependency-tracking --disable-silent-rules --prefix=/usr --exec-prefix=/usr --bindir=/usr/bin --sbindir=/usr/sbin --sysconfdir=/etc --datadir=/usr/share --includedir=/usr/include --libdir=/usr/lib64 --libexecdir=/usr/libexec --localstatedir=/var --sharedstatedir=/var/lib --mandir=/usr/share/man --infodir=/usr/share/info '--bundled-libraries=!zlib,!popt,!talloc,!pytalloc,!pytalloc-util,!tevent,!pytevent,!tdb,!pytdb,!ldb,!pyldb,!pyldb-util' --disable-rpath-install --enable-fhs --systemd-install-services --systemd-nmb-extra=Environment=KRB5CCNAME=FILE:/run/samba/krb5cc_samba --systemd-samba-extra=Environment=KRB5CCNAME=FILE:/run/samba/krb5cc_samba --systemd-smb-extra=Environment=KRB5CCNAME=FILE:/run/samba/krb5cc_samba --systemd-winbind-extra=Environment=KRB5CCNAME=FILE:/run/samba/krb5cc_samba --with-cachedir=/var/lib/samba --with-lockdir=/var/lib/samba/lock --with-modulesdir=/usr/lib64/samba --without-fam --with-pam --with-pammodulesdir=/usr/lib64/security --with-piddir=/run --with-pie --with-relro --with-shared-modules=idmap_ad,idmap_rid,idmap_ldap,idmap_hash,idmap_tdb2,pdb_tdbsam,pdb_ldap,pdb_smbpasswd,pdb_wbc_sam,pdb_samba4,auth_wbc,auth_unix,auth_server,auth_samba4,vfs_dfs_samba4 --with-sockets-dir=/run/samba --with-statedir=/var/lib/samba --with-systemd --with-systemddir=/usr/lib/systemd/system --with-system-mitkrb5 --with-experimental-mit-ad-dc --enable-glusterfs --with-cluster-support --with-profiling-data --enable-selftest

and build fails with:

[2422/3795] Compiling nsswitch/nsstest.c
../../nsswitch/nsstest.c:140:13: error: ‘nss_setpwent’ redeclared as different kind of symbol
  140 | static void nss_setpwent(void)
      |             ^~~~~~~~~~~~
In file included from ../../nsswitch/nsstest.h:53,
                 from ../../nsswitch/nsstest.c:22:
/usr/include/nss.h:186:25: note: previous declaration of ‘nss_setpwent’ was here
  186 | typedef enum nss_status nss_setpwent (int);
      |                         ^~~~~~~~~~~~
../../nsswitch/nsstest.c:155:13: error: ‘nss_endpwent’ redeclared as different kind of symbol
  155 | static void nss_endpwent(void)
      |             ^~~~~~~~~~~~
In file included from ../../nsswitch/nsstest.h:53,
                 from ../../nsswitch/nsstest.c:22:
/usr/include/nss.h:87:25: note: previous declaration of ‘nss_endpwent’ was here
   87 | typedef enum nss_status nss_endpwent (void);
      |                         ^~~~~~~~~~~~
../../nsswitch/nsstest.c:293:13: error: ‘nss_setgrent’ redeclared as different kind of symbol
  293 | static void nss_setgrent(void)
      |             ^~~~~~~~~~~~
In file included from ../../nsswitch/nsstest.h:53,
                 from ../../nsswitch/nsstest.c:22:
/usr/include/nss.h:181:25: note: previous declaration of ‘nss_setgrent’ was here
  181 | typedef enum nss_status nss_setgrent (int);
      |                         ^~~~~~~~~~~~
../../nsswitch/nsstest.c:308:13: error: ‘nss_endgrent’ redeclared as different kind of symbol
  308 | static void nss_endgrent(void)
      |             ^~~~~~~~~~~~
In file included from ../../nsswitch/nsstest.h:53,
                 from ../../nsswitch/nsstest.c:22:
/usr/include/nss.h:82:25: note: previous declaration of ‘nss_endgrent’ was here
   82 | typedef enum nss_status nss_endgrent (void);
      |                         ^~~~~~~~~~~~

Waf: Leaving directory `/home/tkloczko/rpmbuild/BUILD/samba-4.12.2/bin/default'
Build failed
 -> task in 'nsstest.objlist' failed with exit status 1 (run with -v to display more information)
make: *** [Makefile:7: all] Error 1