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Declarative Build Systems

Most software follows common build patterns, such as the classic ./configure && make && make install workflow. In an RPM spec file, maintainers typically need to place these steps in their respective sections. Together with the source unpacking step, this often results in a large amount of boilerplate code. Across many spec files, this boilerplate is nearly identical, with only occasional minor adjustments to accommodate distribution preferences or other details.

To reduce this repetitive boilerplate, openRuyi recommends using the declarative build system, a new feature supported in RPM 4.20 and later. This mechanism allows developers to define these common steps for each build system centrally. When packaging software, maintainers only need to declare the build system they use and, when necessary, provide additional switches or parameters for specific steps.

Usage​

In the simplest case, a spec file only needs to include a build system declaration, for example: BuildSystem: autotools.

That said, cases requiring manual fine-tuning are also quite common. In general, packagers have two ways to achieve this.

Prepend or append​

Packagers may use prepend and append operations as needed.

  • For example, if packagers need to initialize environment variables before the build step, they can add %build -p and write the corresponding commands inside it. Here, -p stands for prepend, meaning the build system inserts the commands before the automatically generated script.

  • Likewise, if packagers need to remove a file after the install step, they can add %install -a and write the necessary commands inside it. Here, -a stands for append, meaning the build system adds the commands after the automatically generated script.

Passing additional parameters​

If packagers need to pass additional parameters, such as build configuration options, they can use the BuildOption tag. The syntax is: BuildOption(<section>): <option string>.

This tag may appear any number of times in the spec file for each section. For example:

BuildOption(conf):  --enable-zsh-secure-free
BuildOption(conf):  --enable-gdbm
BuildOption(build):  all info html
BuildOption(install):  install.info
BuildOption(install):  fndir=%{_datadir}/%{name}/functions
BuildOption(install):  runhelpdir=%{_datadir}/%{name}/help

Please note that you must leave two spaces between the colon (:) and the option string that follows.

Although RPM syntax allows packagers to omit the build stage name after BuildOption, openRuyi requires them to specify it explicitly.