rust2rpm/README.md

# rust2rpm

rust2rpm is a tool for automatically generating RPM spec files for Rust crates.

## `rust2rpm.conf`

If it is present, a `rust2rpm.conf` configuration file is read
by rust2rpm to override some aspects of the automatic spec file generation.

This file can be committed to dist-git to ensure that these settings
will be applied for future updates of a crate package, as well.

The file follows a slightly modified `ini` syntax. It supports sections for
default settings (`[DEFAULT]`) and target-specific settings (i.e. `[fedora]`).

These configuration options are available right now:

- `unwanted-features`: features or optional dependencies for which no
  `+feature` subpackage should be generated (for example, dependencies on Rust
  compiler internals for crates that are also bundled with Rust itself)
- `buildrequires`: additional build dependencies that must be installed for the
  package to build correctly (i.e., `pkgconfig(foo)` for the `foo-sys` crate)
- `lib.requires`: additional build dependencies that must be installed for the
  crate to build correctly as a dependency of another crate (usually, this
  contains the same values as the `buildrequires` option)
- `lib+foo.requires`: additional build dependencies that must be installed for
  the crate to build correctly as a dependency of another crate if it has
  enabled the optional `foo` feature
- `bin.requires`: additional runtime dependencies of the binary application that
  is built from this crate

```ini
[DEFAULT]
unwanted-features =
  compiler_builtins
  rustc-dep-of-std
buildrequires =
  pkgconfig(foo) >= 1.2.3
lib.requires =
  pkgconfig(foo) >= 1.2.3

[fedora]
bin.requires =
  findutils
buildrequires =
lib.requires =
lib+default.requires =
  pkgconfig(bar) >= 2.0.0
```

Note that features and optional dependencies that are marked as
`unwanted-features` must not be dependencies of other Cargo features that are
not marked "unwanted" as well. Failing to consider transitive dependencies will
lead to broken dependencies of generated `rust-foo+bar-devel` packages and / or
errors when generating spec files with rust2rpm.