fix FTBFS

dovecot.spec

@@ -1,5 +1,10 @@
 %global __provides_exclude_from %{_docdir}
 %global __requires_exclude_from %{_docdir}
+
+# FIXME: lto and annobin breaks build atm, retest after 2021-08
+%global _lto_cflags %nil
+%undefine _annotated_build
+
 Summary: Secure imap and pop3 server
 Name: dovecot
 Epoch: 1
@@ -38,6 +43,8 @@ Patch15: dovecot-2.3.11-bigkey.patch
 # not sent upstream as proper fix would use dovecot's lib-dcrypt but it introduces
 # hard to break circular dependency between lib and lib-dcrypt
 Patch16: dovecot-2.3.6-opensslhmac.patch
+
+# FTBFS
 Patch17: dovecot-2.3.15-fixvalcond.patch
 Patch18: dovecot-2.3.15-valbasherr.patch
 
@@ -62,6 +69,11 @@ BuildRequires: libicu-devel
 BuildRequires: libexttextcat-devel
 BuildRequires: libstemmer-devel
 BuildRequires: multilib-rpm-config
+BuildRequires: flex, bison
+BuildRequires: systemd-devel
+%if %{?fedora}0 >= 35
+BuildRequires: glibc-gconv-extra
+%endif
 
 # gettext-devel is needed for running autoconf because of the
 # presence of AM_ICONV
@@ -149,6 +161,7 @@ autoreconf -I . -fiv #required for aarch64 support
 %configure                       \
     INSTALL_DATA="install -c -p -m644" \
     --with-rundir=%{_rundir}/%{name}   \
+    --with-systemd               \
     --docdir=%{_docdir}/%{name}  \
     --disable-static             \
     --disable-rpath              \
@@ -171,7 +184,6 @@ autoreconf -I . -fiv #required for aarch64 support
     --with-solr                  \
     --with-systemdsystemunitdir=%{_unitdir}  \
     --with-docs
-
 sed -i 's|/etc/ssl|/etc/pki/dovecot|' doc/mkcert.sh doc/example-config/conf.d/10-ssl.conf
 
 %make_build