You can customize the rpmbuild command with the options listed in Table 12-1.

Table 12-1 Extra build options for the rpmbuild command

One of the most useful options is --nobuild, which tells the rpmbuild command to not build anything. This may seem silly, but the --nobuild option is very useful for testing whether your RPMs can be built. With the --nobuild option, the rpmbuild command parses the spec file and checks for errors, but does not run any of the build stages.

The --buildroot allows you to specify a different top-level directory for building, overriding the BuildRoot tag in the spec file. This means you can build in a separate location, which is helpful in case there are mistakes. Using a separate directory means the build won’t get mixed with anything else in the build root directory.

The --short-circuit option tells the rpmbuild command to restart at a particular location in the build. Rather than working its way through all the steps up to the build stage you ask for, the --short-circuit option allows the rpmbuild command to restart just at the step you ask for.

Note

This works with the -bc and -bi options only, as well as the -tc and -ti options covered later in this chapter.

For example, if you run the rpmbuild -bc command to stop after the %build section, you can use the --short-circuit option to restart the build at the %build section. If you found a problem in the %build section and corrected it, you can quickly get going again by restarting the build at the %build section rather than extracting all the sources yet again.

This option is most useful when you are compiling a package, hit an error, and fix that error. Without the --short-circuit option, you’ll likely end up spending a lot of time recompiling the code you have already compiled.

During normal development of an RPM package, you will likely execute each build section, one at a time, stop, fix any errors and restart where you left off. You’ll go through this cycle a number of times before the RPM finally builds right.

Warning

Never distribute an RPM made with the --short-circuit option. Instead, once you have everything working, start from scratch and rebuild the RPM. This is to avoid any problems with a partially-created RPM.

The --clean option tells the rpmbuild command to remove the build tree when complete. This helps ensure that the next time you run the rpmbuild command, you are starting from a known situation.

For example:

$ rpmbuild --clean /usr/src/redhat/SPECS/jikes.spec

Executing(--clean): /bin/sh -e /var/tmp/rpm-tmp.98247

+ umask 022

+ cd /usr/src/redhat/BUILD

+ rm -rf jikes-1.17

+ exit 0

You can use the --clean option alone, as shown previously, or in concert with another option such as -bi to build and install a binary RPM. In the latter case, the rpmbuild command will clean the built files after the rest of the command finishes.

Similarly, the --rmsource option tells the rpmbuild command to remove the sources after completing the command. You can call this option with another option, such as -bi for building and installing a binary RPM (and then removing the sources), or alone on the command line to remove the sources only.

For example:

rpmbuild --rmsource jikes.spec

Note

The abbreviation rm is short for remove. It comes from the Linux rm command, used for removing files.

The --rmspec option tells the rpmbuild command to remove the spec file when done with the command. As with the --rmsource option, you can use the --rmspec option in conjunction with another rpmbuild option or on its own to just remove the spec file.

For example:

rpmbuild --rmspec jikes.spec

Warning

The file you are removing with this command is the spec file you are passing to the command. Be careful, because you cannot undo this operation and you have now lost your spec file, except inside your source package.

The --target option tells the rpmbuild command to build a package for another platform. You need to pass the name of the platform. For example:

rpmbuild -bi --target i486-redhat-linux

The basic format is:

cpu-vendor-os

For example, i686-redhat-linux specifies a 686 CPU with Red Hat Linux. Other CPUs include ppc for PowerPC and sparc for Sun SPARC.

Cross Reference

The --target option sets the target architecture at build time. Chapter 4 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.

Warning

Set the target with care. Make sure you can really build executable programs for that architecture.

If you try to compile a system that uses the GNU configure system to configure the build, your target will likely be ignored. For example, if you try to build the aforementioned jikes package with a target of ppc-ibm-aix, to specify IBM’s UNIX, called AIX, on a PowerPC architecture, you will see the target ignored as the configure system detects that it's running on Linux on an i686 architecture.

For example:

$ rpmbuild -bc --target ppc-ibm-aix /usr/src/redhat/SPECS/jikes.spec

Building target platforms: ppc-ibm-aix

Building for target ppc-ibm-aix

Executing(%prep): /bin/sh -e /var/tmp/rpm-tmp.94955

+ umask 022

+ cd /usr/src/redhat/BUILD

+ LANG=C

+ export LANG

+ cd /usr/src/redhat/BUILD

+ rm -rf jikes-1.17

+ /usr/bin/gzip -dc /usr/src/redhat/SOURCES/jikes-1.17.tar.gz

+ tar -xf -

+ STATUS=0

+ '[' 0 -ne 0 ']'

+ cd jikes-1.17

++ /usr/bin/id -u

+ '[' 500 = 0 ']'

++ /usr/bin/id -u

+ '[' 500 = 0 ']'

+ /bin/chmod -Rf a+rX,g-w,o-w .

+ exit 0

Executing(%build): /bin/sh -e /var/tmp/rpm-tmp.15710

+ umask 022

+ cd /usr/src/redhat/BUILD

+ cd jikes-1.17

+ LANG=C

+ export LANG

+ ./configure CXXFLAGS=-O3 --prefix=/tmp/jikesrpm/usr

checking for a BSD-compatible install... /usr/bin/install -c

checking whether build environment is sane... yes

checking for gawk... gawk

checking whether make sets ${MAKE}... yes

checking whether to enable maintainer-specific portions of Makefiles... no

checking build system type... i686-pc-linux-gnu

checking host system type... i686-pc-linux-gnu

checking for g++... g++

As you can see, the command starts out with the target as the platform, but the configure script soon overrides that, as shown at the end of the truncated output.