riscv64: add CFLAGS to workaround fragile test-strptime

This test cannot always get intended result due to different
user address space layout among different archs.

mandoc.spec

@@ -1,6 +1,6 @@
 Name:             mandoc
 Version:          1.14.6
-Release:          2
+Release:          3
 Summary:          A suite of tools for compiling mdoc and man
 
 License:          ISC
@@ -70,7 +70,11 @@ echo 'INSTALL_DATA="${INSTALL} -m 0644"'    >> configure.local
 
 echo 'INSTALL_LIBMANDOC=1' >> configure.local
 
+%ifarch riscv64
+echo 'CFLAGS="%{optflags} -fPIC -Werror=implicit-function-declaration"' >> configure.local
+%else
 echo 'CFLAGS="%{optflags} -fPIC"' >> configure.local
+%endif
 export CC=clang
 ./configure
 %make_build
@@ -220,6 +224,8 @@ fi
 %{_mandir}/man3/tbl.3*
 
 %changelog
+* Mon Oct 9 2023 laokz <zhangkai@iscas.ac.cn> - 1.14.6-3
+- add CFLAGS for riscv64 to workaround fragile test-strptime.c
 * Thu Apr 6 2023 changzhangm <chaozhangm@isoftstone.com> - 1.14.6-2
 - Update to 1.14.6-2
 * Fri Sep 23 2022 chendexi <chendexi@kylinos.cn> - 1.14.6-1