+%ifarch x32
+BuildRequires: glibc-devel(x32)
+BuildRequires: glibc-devel(x86_64)
+%if "%{_host_cpu}" == "x86_64"
+# building on x86_64 host with --target x32-pld-linux
+BuildRequires: curl-devel
+BuildRequires: gcc-multilib-x32
+BuildRequires: libgit2-devel
+BuildRequires: libstdc++-devel
+%{?with_system_llvm:BuildRequires: llvm-devel >= 8.0}
+BuildRequires: openssl-devel >= 1.0.1
+BuildRequires: zlib-devel
+%else
+# building x86_64-hosted crosscompiler on x32 host
+BuildRequires: gcc-multilib-64
+BuildRequires: libstdc++-multilib-64-devel
+# how to specify?
+#BuildRequires: curl-devel.x86_64
+#BuildRequires: libgit2-devel.x86_64
+#BuildRequires: llvm-devel.x86_64 >= 7.0
+#BuildRequires: openssl-devel.x86_64
+#BuildRequires: zlib-devel.x86_64
+%endif
+%endif