Từ tài liệu Fedora cho vòng / phút, tệp spec và rpmbuild:
The --target option sets the target architecture at build time. Chapter 3,
Using RPM covers how you can use the --ignoreos and --ignorearch options
when installing RPMs to ignore the operating system and architecture that
is flagged within the RPM. Of course, this works only if you are installing
on a compatible architecture.
On the surface level, the --target option overrides some of the macros in
the spec file, %_target, %_target_arch, and %_target_os. This flags the RPM
for the new target platform.
Under the covers, setting the architecture macros is not enough. You really
cannot create a PowerPC executable, for example, on an Intel-architecture
machine, unless you have a PowerPC cross compiler, a compiler that can make
PowerPC executables.
http://docs.fedoraproject.org/en-US/Fedora_Draft_Documentation/0.1/html/RPM_Guide/ch-rpmbuild.html
Vì vậy, như đã nói, hãy đảm bảo bạn đã cài đặt trình biên dịch bổ sung (ví dụ gcc.i686 & gcc.x86_64).