Build from Source

By default, rebaze uses system libraries. For hermetic, reproducible builds, you can build dependencies from source using rules_foreign_cc.

System vs Source Builds

Approach	Pros	Cons
System libraries	Fast, simple setup	Non-hermetic, version varies
Source builds	Hermetic, reproducible	Slower first build

Configure Source Strategy

In rebaze.toml:

[strategy]
default = "source"

Or for specific packages:

[strategy]
default = "system"

[strategy.overrides]
zlib = "source"
openssl = "source"

Define Package Metadata

For packages built from source, define their metadata:

[mappings.known_packages.zlib]
version = "1.3.1"
url = "https://github.com/madler/zlib/releases/download/v1.3.1/zlib-1.3.1.tar.gz"
sha256 = "9a93b2b7dfdac77ceba5a558a580e74667dd6fede4585b91eefb60f03b72df23"
strip_prefix = "zlib-1.3.1"
build_system = "cmake"
out_static_libs = ["libz.a"]

[mappings.known_packages.openssl]
version = "3.2.0"
url = "https://github.com/openssl/openssl/releases/download/openssl-3.2.0/openssl-3.2.0.tar.gz"
sha256 = "..."
strip_prefix = "openssl-3.2.0"
build_system = "autotools"
out_static_libs = ["libssl.a", "libcrypto.a"]
deps = []
build_options = ["no-shared"]

Supported Build Systems

Value	Tool Used
`cmake`	`cmake_external` from rules_foreign_cc
`autotools`	`configure_make` from rules_foreign_cc
`meson`	`meson` from rules_foreign_cc

Generated Files

When using source strategy, rebaze generates:

`third_party/source.bzl`

load("@rules_foreign_cc//foreign_cc:defs.bzl", "cmake")

def _zlib_impl():
    cmake(
        name = "zlib",
        lib_source = "@zlib//:all_srcs",
        out_static_libs = ["libz.a"],
    )

`MODULE.bazel`

bazel_dep(name = "rules_foreign_cc", version = "0.14.0")

http_archive = use_repo_rule("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")

http_archive(
    name = "zlib",
    url = "https://...",
    sha256 = "...",
    strip_prefix = "zlib-1.3.1",
)

Troubleshooting

Build fails with missing headers

Add transitive dependencies:

[mappings.transitive_deps]
curl = ["zlib", "openssl"]

Wrong library output name

Check the actual output name:

out_static_libs = ["libz.a"]  # Linux
# or
out_static_libs = ["z.lib"]   # Windows