feat: add rustc buildenv for rust self-packaging

Author: mikonse

Cargo.lock

@@ -1,4 +1,4 @@
-debmagic (0.1.0) UNRELEASED; urgency=medium
+debmagic (0.0.1-alpha1) UNRELEASED; urgency=medium
 
   * WIP: Initial release.
 

debian/changelog

@@ -1,4 +1,6 @@
 #!/usr/bin/env python3
+import shutil
+import os
 
 import sys
 from pathlib import Path
@@ -19,12 +21,23 @@ pkg = package(
     preset=[dhp],
 )
 
+os.environ.update({
+    "PATH": f"/usr/share/cargo/bin:{os.environ['PATH']}",
+    "CARGO": "/usr/share/cargo/bin/cargo",
+    "CARGO_HOME": f"{Path.cwd()}/debian/cargo_home",
+    "CARGO_REGISTRY": f"{Path.cwd()}/debian/cargo_registry",
+    "DEB_CARGO_CRATE": f"{pkg.build_env.DEB_SOURCE}_{pkg.build_env.DEB_VERSION_UPSTREAM}"
+})
+
 packages = {
     "python3-debmagic-common": ("packages/debmagic-common", "debmagic-common"),
     "debmagic": ("packages/debmagic", "debmagic"),
     "debmagic-pkg": ("packages/debmagic-pkg", "debmagic-pkg"),
 }
 
+debmagic_cargo_lock = Path("packages/debmagic/Cargo.lock")
+debmagic_cargo_lock_saved = Path("packages/debmagic/Cargo.lock.saved")
+
 def dh_auto(build: Build, stage: str, use_destdir: bool = False):
     for pkg_name, (path, python_pkg_name) in packages.items():
         destdir = f" --destdir debian/{pkg_name} " if use_destdir else ""
@@ -38,6 +51,8 @@ def dh_auto_configure(build: Build):
 
 @dhp.override
 def dh_auto_build(build: Build):
+    if debmagic_cargo_lock.is_file():
+        shutil.move(debmagic_cargo_lock, debmagic_cargo_lock_saved)
     dh_auto(build, "dh_auto_build")
 
 
@@ -53,6 +68,8 @@ def dh_auto_test(build: Build):
 
 @dhp.override
 def dh_auto_clean(build: Build):
+    if debmagic_cargo_lock_saved.is_file():
+        shutil.move(debmagic_cargo_lock_saved, debmagic_cargo_lock)
     dh_auto(build, "dh_auto_clean")
 
 

debian/rules

@@ -0,0 +1,45 @@
+"""
+Implement the build environment logic provided by /usr/share/rustc/architecture.mk
+"""
+
+
+def _rust_cpu(cpu: str, arch: str) -> str:
+    # $(subst i586,i686,...)
+    cpu = cpu.replace("i586", "i686")
+
+    if "-riscv64-" in f"-{arch}-":
+        return cpu.replace("riscv64", "riscv64gc")
+    elif "-armhf-" in f"-{arch}-":
+        return cpu.replace("arm", "armv7")
+    elif "-armel-" in f"-{arch}-":
+        return cpu.replace("arm", "armv5te")
+
+    return cpu
+
+
+def _rust_os(system: str, arch_os: str) -> str:
+    if "-hurd-" in f"-{arch_os}-":
+        return system.replace("gnu", "hurd-gnu")
+    return system
+
+
+def _get_rust_type(prefix: str, env_vars: dict[str, str]) -> str:
+    cpu = env_vars.get(f"{prefix}_GNU_CPU", "")
+    arch = env_vars.get(f"{prefix}_ARCH", "")
+    system = env_vars.get(f"{prefix}_GNU_SYSTEM", "")
+    arch_os = env_vars.get(f"{prefix}_ARCH_OS", "")
+
+    r_cpu = _rust_cpu(cpu, arch)
+    r_os = _rust_os(system, arch_os)
+
+    return f"{r_cpu}-unknown-{r_os}"
+
+
+def build_rustc_build_env(env: dict[str, str]):
+    for machine in ["BUILD", "HOST", "TARGET"]:
+        var_name = f"DEB_{machine}_RUST_TYPE"
+        env[var_name] = _get_rust_type(f"DEB_{machine}", env)
+
+    # Fallback for older dpkg versions (ifeq check)
+    if env["DEB_TARGET_RUST_TYPE"] == "-unknown-":
+        env["DEB_TARGET_RUST_TYPE"] = env["DEB_HOST_RUST_TYPE"]

packages/debmagic-pkg/src/debmagic/v0/_dpkg/_rustc_build_env.py

@@ -6,6 +6,8 @@
 from debmagic.common.models.package_version import PackageVersion
 from debmagic.common.utils import run_cmd
 
+from ._rustc_build_env import build_rustc_build_env
+
 
 def _cmd(cmd: str, input_data: str | None = None, env: dict[str, str] | None = None, cwd: Path | None = None) -> str:
     return run_cmd(cmd, check=True, env=env, input=input_data, text=True, capture_output=True).stdout.strip()
@@ -75,4 +77,7 @@ def get_pkg_env(package_dir: Path, maint_options: str | None = None) -> tuple[di
 
         result["ELF_PACKAGE_METADATA"] = json.dumps(elf_meta, separators=(",", ":"))
 
+    # rustc/architecture.mk
+    build_rustc_build_env(result)
+
     return result, version